Test Kitchen Confidential: Lightened Baked Chocolate Mousse

Baked mousse is a classic dessert whose precise origins are unclear. It’s one of those confounding dishes (like, for example, the Japanese practice of putting crispy tempura into soup) in which a finished whipped mousse—cold, rich, a perfect balance of density and airiness—is popped into the oven. What results is a marriage of traditional chilled mousse and a fudgy flourless chocolate cake: silky smooth mousse texture with more substance in the mouthfeel and a ramped-up chocolate flavor.

These qualities are usually achieved with three key parts: a flavor agent (in this case chocolate), a meringue, and lots of heavy cream. Basically, it’s a dance of sugar and fat, in fine balance—a good example of the chemistry and physics of baking. Creating a light version was going to be tricky. We did it by “unpacking” the dessert and addressing each component separately.

Meet Deb Wise, our go-to baking expert. For this project, Deb began by cooking the full-fat-and-calorie version of the recipe to set a benchmark for flavors, mouthfeel, and chocolate intensity.

We had to decrease the amount of chocolate in our baked mousse, as it contributes a significant amount of saturated fat. But we didn’t want to risk losing that deep, intense chocolate flavor.

Tweak: Using our nutrition analysis software, we simply reformulated the recipe by cutting the chocolate back a smidge and increasing the number of servings—not a cheat because dessert portions are often too big anyway.

Result: Fine flavor, but portion size was just too small to fit our nutrition rules. Another problem: 70% of the calories still came from fat, and most of it saturated. This was not a balanced, healthy dessert.

2nd Tweak: Deb tinkered with adding good unsweetened cocoa to replace the additional chocolate we were cutting. The cocoa laid a deep, dark chocolate foundation with very little fat, and we were still able to use 5 ounces of chocolate.

Result: Chocolate challenge solved.

Reducing chocolate also reduced volume. We needed the “loft” of egg whites but had to make sure they wouldn’t deflate. Meringue usually consists of egg whites beaten to stiff peaks. But whites in “peak” condition have expanded as much as possible and can only go down from there. We needed eggs that would puff up as they cooked—and hold that structure out of the oven.

Tweak: Deb did something radical by baking standards: She added whole eggs to the meringue, unheard of because fat prevents the whites from beating to stiff peaks. That was the method to her madness, though: The moderating influence of eggs would keep the meringue at soft peaks—getting air, but not too much—leaving room for expansion in the oven.

Result: Volume issue solved.

Deb preferred sacrificing sat fat–heavy whipping cream–if it meant she could keep as much chocolate as possible. But cutting the cream also affected the creamy texture.

Tweak: More radical thinking from Deb. “What would happen if I baked Cool Whip?” This idea approached the surreal: Wouldn’t the oil-and-milk suspension (which hearkens back to 1967) deflate into a pool? We had never heard of baking it before. A few examples pop up on Google, but nothing like this. Deb folded in 1-1⁄2 cups (replacing a like amount of whipped heavy cream), crossed her fingers, and pushed the springform pan in the oven. It baked beautifully. There was almost no visual—or textural—difference from the cream version. But there was a nutrition difference, a savings of 6.7 grams of total fat and more than 4 grams of saturated fat per serving (which would eat up about 20% of your daily sat fat limit).

Result: Creamy, dense texture and rich mouthfeel.

In the End: It's a fantastic cake, and that's where we left it.