P&Q: michel rostang’s double chocolate mousse cake

Questions about this cake? Ask them here. Did you run into any issues while baking? Let us know!

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34 Responses to “P&Q: michel rostang’s double chocolate mousse cake”

  1. Elaine Corwin January 17, 2011 at 1:16 PM #

    Part of the bottom layer oozed out while baking. It could have been a problem with not whipping the egg whites stiff enough, I’m not sure.

  2. Katya January 17, 2011 at 1:56 PM #

    Elaine, some of mine oozed as well. I think it had to do with the level fit of my pan on the sheet–maybe not perfect. I got a great cake anyway, and tried it warm and cool.

  3. Nina January 17, 2011 at 2:05 PM #

    Mine oozed out as well…thought it was the shape of the old springform I used. More importantly–mine didn’t puff? Did I overmix the egg whites? Is this similar to a souffle where you don’t want to overmix the whites with the chocolate? How long did everyone beat the egg whites—not sure if mine are over or under beaten. Defintely going to have to do a “do-over” on this one.

    • gaaarp January 20, 2011 at 5:55 PM #

      Mine oozed, too. If I make this again, I will use the whole springform pan, not just the ring. My pan is new, so I don’t think the shape contributed to leaking. I had it on a cookie sheet instead of a jellyroll pan, so it leaked all over the bottom of the oven.

  4. frolickingnightowl January 17, 2011 at 2:05 PM #

    Any great ideas for a replacement for the coffee? Just water? Maybe some kind of flavored water?

    Also, I think we ran into this problem with the apple cakes, but it seems like most of us have 9″ pans … should we just do 1 1/2 times the recipe if we want to use a 9″ pan??

    • Nina January 17, 2011 at 2:21 PM #

      Frolick—you can definitely sub water for coffee. The coffee is just acting as a “flavored water”….so you can sub water or another “flavored” water if you prefer. Sorry, can’t help you on the 9in pan….I think I am the only one with an 8inch and no 9inch springform pan!

    • gaaarp January 20, 2011 at 5:56 PM #

      My springform is 9 inches, too. I think to do it over again, I would actually double the recipe. It was so flat!

    • franklyentertaining January 20, 2011 at 7:04 PM #

      I’m trying hot chocolate as a sub for the coffee. It’s in the oven now – I’ll let you know how it goes!

    • SugarPlumFairy January 21, 2011 at 11:50 AM #

      Hii , i tried hazelnut syrup with hot water for one batch and it was perfectly fine:-) will post pics soon:-)

  5. mardi@eatlivetravelwrite January 17, 2011 at 3:20 PM #

    I had a few issues with this:
    1. The cake oozed a little out of the bottom. Not much but definitely a tight fit on the tray so I am not sure why.
    2. The cake did not puff up hardly at all – barely 3/4 inch.
    3. When I cooled the cake base, it shrunk away from the springform edges so I hat to put a circle of parchment paper around when I tipped the next layer of mousse in to bake it.
    4. It still did not puff up with the second layer on – in total it was about 1.5 inches high – if that…
    6. With one half of the cake, I cut out tiny rounds and served those – much more elegant that the big old flat cake.

    I am wondering why it did not puff at all -and will definitely do a re-make – perhaps in a much smaller springform (though I used the right sized one)

  6. KY January 17, 2011 at 4:17 PM #

    Finally, the P&Q is out. I had wanted to know if we could leave little lumps of egg white in the batter when folding the egg white in. I whipped the whites till stiff (did the bowl-turned-upside-down test) and when I folded them into the batter it broke into lumps. I did not fold till the lumps were all gone in case I deflate the whites.

    The second layer did puff and after it sank the top lifted off the cake so there was a thin cracked layer that was lifting off the rest of the cake. Didn’t look like Dorie’s cake at all but it tasted very good.

    I used an 8″ pan with a bottom that can be pushed up and out of the ring. I baked the cake with the base in the pan so just a touch of batter leaked out.

    • Mary January 17, 2011 at 10:33 PM #

      I think it’s better to leave some small streaks of white than to overfold, as it will deflate the whites and the batter. Now, I haven’t made this yet, but it sounds like your whites were overbeaten. They should still be shiny and moist, and not break up into pieces when adding to another mixture.

      • KY January 18, 2011 at 7:53 PM #

        Thanks, Mary. I think you’re right about me overbeating the eggs. I stopped beating (using a stand mixer) when the peaks were firm but the whites could still move around the bowl and the bottom was still a little wet so I gave it a quick mix and beat it again!

  7. Nina January 17, 2011 at 9:12 PM #

    Well, I have made this 3 times today and clearly have an issue with the egg whites since this is not puffing in the oven. I have made sure the bowl is clean and dry and there is no yolk in the whites….but they are not turning out right. Think I am probably overmixing them….how long is everyone beating them and on what speed? Almost seems like this is to be treated more as a souffle? I am not giving up—am going to get this right….just not tonight as I am now out of chocolate!

  8. Kat January 17, 2011 at 9:57 PM #

    I noticed that my spring-form pan had gaps between it and the sil-pat underneath, so using string, I tied the spring-form pan down to the pan (a heavy duty half sheet) like a package. I plopped in some of the batter, which wasn’t terribly runny, and thought everything would be okay.

    I had quite a bit of seepage still. but I just trimmed those bits off before I added and baked the second layer of mousse. The dessert was somewhat flat and fairly dense, but very tasty! Seemed like a lot of work overall for what was essentially an elegant brownie. I’ll make it again to see if I can improve upon today’s result.

    Does anyone else have any thoughts on how to keep the mousse from leaking?

  9. Candy January 17, 2011 at 11:27 PM #

    I was very close to over-beating my whites – in fact, I probably did, but not so much that I wasn’t able to fold them in. The trick is to get them fluffy, without letting them get to the point of turning “chunky”. I knew I was taking too long when I did mine. My suggestion is to keep checking as you beat them. Also, while a fabulous stand mixer is great, it can go from perfect to a bit over-done quickly. I’d err on the side of too soft. Just sayin’

    All of that said, I’ll bet everyone’s tasted amazing… I’ll keep my comments for Friday, but… I don’t see any way that a little less fluffy will make chocolate, eggs, a bit of sugar and butter any less wonderful!

    Oh, and I did 2 layers of parchment – one sheet for the pan, and I happen to have these fancy ones that fit the round pan – so maybe that helped. Also, I kept the side down that the botom fits into – all of those creases in the metal, but mine didn’t leak (the right consistency might have helped too – it was very “mousse-like” so held its shape), not very like a batter. Of course, I can’t get it off the paper….

    • Kat January 18, 2011 at 12:01 AM #

      My mousse was stiff enough that I had to work to smear the third around to cover the area of sil-pat inside the ring, and stiff enough to prevent the spatula from toppling immediately over, but in the warmth of the oven it “melted” and seeped. I probably shouldn’t have used the word batter–it was misleading. :~)

      I had no problem with sticking to the sil-pat, so I’m wondering if the parchment you used gave it something to cling to, preventing the seepage from happening?

  10. Kat January 18, 2011 at 12:02 AM #

    Can anyone think of something “stickier” than a sil-pat, but less sticky than parchment??

  11. mauitn January 18, 2011 at 3:47 PM #

    Since we have a leaking problem, has anyone baked this with the bottom of the spring form pan in?

    • napangel January 18, 2011 at 4:58 PM #

      After reading all of comments are leaking, I think that’s what I’m going to try.

  12. Dorie January 18, 2011 at 7:02 PM #

    All this leaking … ugh and sorry. There is often a little seepage with these kinds of cakes, but this is sounding more serious. I think Mauitn is right, why not bake the cake with the bottom of the springform pan in place? Perhaps it would be best to line the bottom of the pan with a parchment circle.

    Excessive leaking might have to do with how the eggs are beaten and folded into the mousse.

    Beating the egg whites properly is a very important step in the process and Mary is right: the egg whites should hold peaks, but they must still be glossy. Once you lose the gloss on beaten egg whites, you lose their puff power too. When your egg whites break into clouds, it’s a sign that you’ve overbeaten them.

    As for folding the whites into the mousse, it’s better to leave a few white streaks if necessary than to overwork the batter and knock the air out of the whites.

    You should get some puff on the first baked layer and then the puffed layer should deflate, leaving an indentation. You might not have gotten the puff-and-sink if you used a larger springform — there’s not that much mousse/batter to begin with, so stretching it won’t leave enough for a good puff and an equally good depression.

    I’ll keep checking in to see how things are going.

    • Kat January 18, 2011 at 8:20 PM #

      Hi Dorie!
      The fact that you are paying attention is, well, just wow! My mousse yield was almost precisely 5 cups…do yo think that’s about right, or did I overbeat and lose volume?

  13. adamsclewes January 18, 2011 at 8:15 PM #

    Same issue lots of others are having with the 8″ vs. 9″ springform. I actually drove around looking for one this time but to no avail. So the result was a little flat but I thought very flavorful. I made it for my 10 year-old’s birthday party. The kids loved it. My husband thought it was like a very nice brownie but the kids poo pooed him. Thicker would have been better to provide a contrast in textures. Simple and nice flavors.

  14. stoutkitty January 18, 2011 at 9:11 PM #

    I also had the 9 inch pan. I didn’t have any leaking at all. I used parchment paper under mine. I folded my egg whites leaving it so you could see the whites. I was hoping I was doing it right since this was my first time making a mousse of any kind let alone a mousse cake. I don’t think mine puffed up as much as it looked in the book but I figured it was the pan size. Over all this was a hit in my home served warm with homemade whipped cream.

    • StephIrey January 18, 2011 at 10:40 PM #

      I used a 9″ also but increased the recipe by 25% (finally found an 8″ today, so will retry on Thursday if I have time)…had a little leakage, but not too bad, but no “puff” on either layer. I think I definitely overbeat my whites…they lost their gloss, but weren’t “chunky” yet. I’ll leave the review for Friday.

  15. ebessen January 19, 2011 at 9:02 AM #

    Did not have leaking. Cake ended up about 1 inch high. I did the last option of baking the bottom twice and top once and then putting in frig. for 4 hours. Should have kept a better eye on the cake the second time of baking. Was waiting for it to start cracking and cake got very dark almost to a burnt state for the 30 minutes. Next time will probably take it out around 20-25minutes. Served it
    chilled and half the cake was consumed last night the rest was eaten for breakfast.

  16. Vegan Thyme January 20, 2011 at 11:07 AM #

    Uh, I know my gateau problem is “unique” in that my recipe turned into a whole vegan substitution nightmare! Baked bottom part was a complete disaster, sort of what I went through with my vegan brownie attempts: sticky, globby, goo. I was sad. My mousse however, worked well (not great–but edible at least). I used a vegan product Ener-G egg replacer which whipped up foamy (not close to what egg whites would have been). I saved the mousse–(it’s chocolate!) used as “breakfast” topping over my oatmeal this morning! Yum! Light and creamy-ish, sort of like pudding–but not quite set! My challenge is with the EGG. Always is. For the yolk, I used a bit of whipped silken tofu, 2 tablespoons per egg–maybe I should cut back, use 1 tablespoon per egg yolk and add a bit of canola oil to replace yolk’s “fat”, maybe 1 teaspoon per four yolks. I may also need to add some flour to the first layer, otherwise, I am not confident I will come close to having a “firm” anything. I do not own an 8″ springform pan either, but have TWO 9″: Why?! Second attempt going on now. I hope the vegan gremlins stay away this time!

  17. Candy January 20, 2011 at 11:27 AM #

    Despite any of these little trials, this is well worth making. I’m excited to hear everyone’s stories and how they served it. Sneak preview… There was a lot of “mmmmmmmm”, people not wanting to even stop to say how wonderful they thought it was. And that was for leftovers!

  18. Kate January 20, 2011 at 4:33 PM #

    This cake was excellent! It was quick and easy…but more importantly, delicious! It wasn’t overly sweet and had a very nice deep chocolate flavor. I had to use a 9 inch pan so I knew it wouldn’t puff like it would have had I used the proper size pan. Still, it did puff up nicely. There was only a tiny bit of ooze.

  19. kitchenarian January 20, 2011 at 10:08 PM #

    I did not have a problem with leaking in the oven, but I am part of the “over beating the egg whites” crowd. It did not poof in the oven as it was supposed to. I have no doubt it will still be delicious, but I will make it again to see if I can get it right. (Just not tonight.)

  20. Beth January 25, 2011 at 8:04 PM #

    I can’t believe I haven’t made this yet! I was fortunate enough to taste this last summer at Michel Rostang’s restaurant in Paris. Phenomenal! A beautiful experience and an exceptional cake. This will be our perfect Valentine’s Day indulgence.

  21. AguirreEarlene29 February 27, 2011 at 5:11 PM #

    Houses are expensive and not every person can buy it. But, home loans was invented to help different people in such hard situations.


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