As you may have guessed from all of the cupcake recipes, I’m kind of a sucker for all things teeny tiny. Cuteness factor aside, whether you’re making dessert for a small crowd (or just yourself – this is a no-judgment-about-not-so-single-serving-desserts-made-single-serving zone) or you’ve finally decided to bite the bullet on the whole “eating well” thing but still get hit by the occasional sweet tooth, tiny treats are the best. So when I saw this gorgeous mousse cake while
falling down the rabbit hole that is exploring Pinterest, I just had to make it in miniature. It just becomes that much more cute (and self-indulgence and/or diet-friendly)!
To keep things simple, there’s no gelatin or egg or the 30,000 other ingredients that apparently normally go into stabilizing mousse – just whipped cream! After all, the white chocolate already has the whole creamy thing going on, so it just made sense to use whipped cream to provide the volume and general colloidal-ness (which is, by the way, just a fancy not-quite-a-real-noun-version-of-a-real-adjective that means stuff suspended in other stuff, like the air that’s suspended in the cream in whipped cream) that makes mousse so fluffy and mousse-y.
(And it has nothing to do with the fact that I always have the worst time getting gelatinous mixtures to whip up properly. Absolutely nothing.)
So what does this recipe entail? Not much – just two layers of airy whipped cream folded into silky smooth white chocolate, one of which features a healthy dash of matcha sprinkled throughout, all supported by a fluffy layer of matcha sponge cake. In terms of decorating tips, do not skimp on the top layer of dusted matcha powder – even though the recipe doesn’t call for any sugar in either of the mousse layers, do not underestimate the propensity of white chocolate to impart a ridiculous amount of sweetness that desperately needs to be cut by the bitter matcha on top. Also, if you’re feeling extra fancy, feel free to mount a lacy white chocolate heart (directions here!) on top of a swirly dollop of extra whipped cream.
So whether you’re staving off a serious matcha craving (which is, by the way, basically my standard state of being), need a recipe for something sweet and teeny tiny for whatever reason you so choose, or want a practical and delicious way to geek out over colloids, this recipe’s totally got your back. Hope you enjoy!
Matcha Mousse Cake
Makes one 4″ mini mousse cake
Inspired by Washoku
Matcha Sponge Cake:
1 egg, separated into yolk and whites
25 g sugar
25 g all purpose flour
1 tsp matcha powder
1 drop green food coloring (optional, but makes for a prettier product!)
White Chocolate and Matcha Mousse:
1/2 cup white chocolate chips
1-2 tbs heavy cream
1/2 tsp matcha powder
2/3 cup heavy cream
1 bar white chocolate (you won’t use all of it, but it’s easier to shave a bigger bar!)
12 white chocolate chips
Matcha Sponge Cake:
- Preheat the oven to 325 ºF. Using parchment paper, line the bottom of a 4″ springform pan.
- Using a hand mixer or a whisk (1 egg white is too little for the stand mixer to properly whisk!), beat the egg white to the firm peaks stage. At this point, when you lift out the whisk or beaters, a well-defined peak with a point that curls over should form.
- Using a whisk, beat together the egg yolk, sugar, and green food coloring until the sugar is fully dissolved.
- Fold the egg yolk mixture into the whipped egg whites until most of the yellow streaks are gone, then sift in the flour and matcha powder. Fold the mixture until the dry ingredients are just incorporated.
- Fill the springform pan with batter to a depth of about 1/4″ to 1/3″, then bake for 10-12 minutes, or until the center of the cake feels springy when poked gently with a finger. Set aside to cool completely. Remove the cake from the pan, gently peel off the parchment paper, and set the layer back in – this will make removing the cake from the pan much easier once everything is assembled.
Tip: You will definitely have too much batter because it doesn’t really make too much sense to use half of an egg in a recipe, no matter how tiny the cakes are supposed to be. You should have enough batter leftover for a couple of mini cupcakes though (a treat to reward the baker?), and who ever complained about a couple of extra mini matcha cupcakes?
White Chocolate and Matcha Mousse:
- In the microwave, melt the white chocolate chips together with 1 tbs heavy cream, removing to stir at 15 second intervals. Add the second tablespoon of cream as needed until the mixture reaches the consistency of icing. Allow to cool to room temperature.
Tip: Melt the chocolate as soon as you pop the cake into the oven to streamline the cooling process! Also, at room temperature, your mixture should have the consistency of thick icing (or something vaguely like the “molten lava” of unbaked macarons. That description’s always confused me – how on Earth does harmlessly delicious macarons resemble terrifyingly hazardous liquified rock? More importantly, why are we all collectively supposed to be familiar with the consistency of terrifyingly hazardous liquified rock?) If it is too thick, stir in extra cream as needed. A total of 2-ish tbs usually does the trick for me, but as long as your consistency is a little closer to pudding than hot cocoa, a slightly thinner mixture won’t hurt and might actually make the step 3 a bit easier!
- Divide the white chocolate mixture into 2 bowls, then sift in the matcha powder (plus a bit of cream to adjust the consistency as needed) into one of the bowls. Stir until well combined.
- In a stand mixer, whip the remaining heavy cream to the firm peaks stage. Divide the whipped cream into 2 bowls, then add 1 bowl of divided white chocolate mixture into each bowl. Gently fold the contents until just combined.
- Fill the springform pan with the matcha sponge layer about halfway full with the white chocolate mousse, roughly smooth off the top surface with a spoon, then top off the pan with the matcha mousse. For a perfect finish, smooth off the top by dragging a large offset spatula across the top of the pan. Set aside to cool for at least 2 hours to allow the mousse to set!
- Using a vegetable peeler, shave about 2 rows of squares off of the white chocolate bar.
- Carefully remove the set mousse cake from the springform pan, then set onto a large plate. Gently press the white chocolate shavings onto the sides of the cake, allowing the excess to fall onto the plate.
- Using a small sieve, dust the top of the cake with matcha powder.
- Using an offset spatula and a sharp knife, gently lift the cake out of the bottom of the springform pan and onto the serving plate.
Tip: To lift, wedge the offset spatula under the edge of the cake, gently lift the edge high enough for the knife to slip under and hold the cake in place, then slide the offset spatula all the way under the cake, gently lifting in one smooth motion. To plate, set down the edge of the cake that is closer to the tip of the spatula, gently tilt the spatula back down until it is nearly parallel with the surface of the table, balance the cake in place using the tip of the knife, then slide out the spatula, then the knife.
- Top with white chocolate chips and shavings. Enjoy!