Genoise Mousseline

This French sponge cake gets its lift entirely from eggs. No baking powder, no baking soda, no butter. Whole eggs plus extra yolks are warmed with sugar over simmering water, then beaten on high speed until the mixture is cold, pale, and tripled in volume. That’s the foundation of a genoise, and it’s where all the texture comes from.

The warming step is critical. It dissolves the sugar and loosens the egg proteins so they can trap more air when whipped. Skip it, and you’ll get a dense, flat cake instead of the light, springy layers this technique is known for.

Sifting the cake flour and cornstarch together multiple times ensures they’re fully aerated before folding into the eggs. Dump heavy flour into a delicate foam and you’ll knock out all the air you just worked to build.

Kitchen Tips

• Fold the flour in by hand with a large spatula. A mixer deflates the batter. Use slow, sweeping motions from the bottom up.
• Line the bottom of the springform pan with parchment. The cake releases cleanly and you avoid tearing that delicate crumb.
• Remove from the pan immediately after baking. Leaving it in traps steam and makes the bottom soggy.
• The genoise is meant as a base layer. Soak it with a flavored syrup (coffee, liqueur, citrus) before filling and frosting.

Variations

• Add a teaspoon of vanilla extract to the egg mixture for a more fragrant cake.
• Use this as the base for a classic strawberry shortcake with whipped cream and fresh berries.
• Split the cake into two layers and fill with pastry cream or mousse for an elegant French-style dessert.