The Secret Way to Make Sponge-Style Cakes with Boxed Cake Mix
If you have ever watched a baking show, you know that sponge cakes are a big part of a lot of other recipes. These light, flexible cakes are ideal for all sorts of bakes, from rolled cakes to trifles, to serving as layers in all sorts of fabulous treats. But sponge cakes can be a bit fussy and time consuming for your regular home baker. Which is why I lean into this sponge cake hack. By using a boxed cake mix, and adjusting some of the technique, I end up with a perfectly serviceable sponge in much less time and with much less effort than most "from scratch" recipes.
How to make sponge cake from a boxed cake mix
You can make your sponge in any flavor you like; I tend to use the vanilla or white styles since that gives me more flexibility in fillings and frostings, but as long as the mix does not contain any nuts or chips, you can let your imagination run wild!
For an elegant dinner party dessert, I bake the cake in a sheet pan, roll it up in a tea towel while still warm, then spread with any flavor of jam I like, cut into one-inch slices, and line a glass bowl with the spirals. Then I fill the bowl with chocolate mousse and let set in the fridge overnight before unmolding for version of a Charlotte that is a serious showstopper. It is also a great cake to make petit fours: Just spread a bit of jam or frosting between two thin layers and stack, then cut into small cubes and cover in icing.
Cake Mix Sponge Cake
1 box cake mix, any flavor (I use Duncan Hines)
3 large egg whites
1/3 cup neutral oil
1¼ cups water
1. Sift the cake mix to remove any lumps. This is essential, as you will be folding this mix together and do not want any unmixed lumps of mix interfering with texture. Set aside.
2. In a medium clean bowl with an electric mixer or in your stand mixer with the whisk attachment, beat the egg whites to stiff peaks.
3. Add the oil and water to the cake mix and stir until smooth. Then whisk in 1/3 of the egg whites to lighten the mixture. Then gently fold in the rest of the whites with a large rubber spatula, being careful not to deflate the whites, and mixing just until you see no more streaks of whites in the batter.
4. Transfer to the prepared pan of your choosing and bake at 325° until the cake springs back when gently touched and a skewer comes out clean.
5. Let cool on a rack for 10 minutes before removing from the pan, then cool completely to room temperature before filling or frosting. If your recipe calls for other preparations, such as pre-rolling the cake, follow those instructions.