A lovely, layered dessert known as a “magic cake” has been pipping up on blogs all over the place lately. The cake is a dessert which magically turns itself into layers of cake and custard while baking in the oven, and it reminds me a lot of an impossible pie. Impossible pie is a type of custardy dessert that has a small amount of flour in it which allows a distinct “crust” to form during baking and give the pie two layers with very little work. Magic cake works in a very similar way, but has the custard on the bottom, rather than on the top like the impossible pie.
Magic cake is quite easy to make and this version of it uses buttermilk for a wonderfully tangy, buttery flavor that is addictive. The cake starts by mixing up a thin batter, using a relatively small amount of flour for a cake batter, then egg whites are folded in to it. It is difficult to directly fold the egg whites into the batter because it is so fluid, so I recommend stirring some in to thicken the batter (it’s ok if they loose a little volume) and then fold in the rest. The cake is baked at a low temperature and it separates into a sponge cake-like top layer and a dense custardy layer underneath. Unlike a pudding cake, the custard here is quite firm and very easy to slice through once the cake has set and cooled.
The vanilla and buttermilk cake is delicious, with a dense and custardy texture that you won’t find in any other kind of cake. I am a big custard fan and I am more than happy to eat this delicious cake plain. Buttermilk and vanilla go with all kinds of flavors, however, and this is a great base recipe to dress up. It is fantastic when served with fresh berries and whipped cream, and a drizzle of maple syrup is a simple – but amazing – way to finish it off just before serving, too.
This cake is baked in an 8 x 8-inch square baking dish. You can opt for a round dish of similar size. The depth of the pan is part of what makes this cake nice and custardy at the bottom, so while you could use a 9-inch pan in a pinch, you might not get quite as clear of a custardy layer as you would in the slighlty smaller pan.
Buttermilk Magic Cake
4 egg yolks, room temperature
3/4 cup sugar
1/3 cup butter, melted and cooled
3/4 cup all purpose flour
1/4 tsp salt
2 1/4 cups buttermilk, room temperature
2 tsp vanilla extract
4 large egg whites, room temperature
1 tbsp sugar
Preheat oven to 325F. Lightly grease an 8×8-inch square baking pan.
In a large bowl, beat together egg yolks and sugar at medium-high speed until doubled in volume. Beat in melted butter, then sift in the flour and salt and mix until well-combined. At low speed, gradually blend in the buttermilk and vanilla.
In a medium bowl, whip egg whites until foamy. Beat in 1 tbsp sugar, then continue to beat the egg whites on high speed until stiff peaks form.
Whisk half of the egg whites into the buttermilk mixture until well combined. The buttermilk mixture will be fluid, so don’t worry if the egg whites lose some volume. Once half of the egg whites have been incorporated, fold in the remaining half with your whisk.
Pour into prepared pan.
Bake for about 60 minutes, until the cake is set and jiggles (but is not liquidy) when the pan is gently shaken and the top is golden brown.
Allow to cool completely before slicing.