1

If you are making round cakes, preheat the oven to 350°F and butter and flour two 9-inch round cake pans. If you are making sheet cakes, preheat the oven to 375°F and line two 13 by 17-inch sheet pans with parchment. Combine the almond flour, cake flour, and 1/2 cup of the granulated sugar in a food processor. With the motor running, add the eggs, 2 at a time, until the mixture is smooth.

2

Transfer the mixture to a bowl large enough to hold all the batter.

3

Beat the egg whites with the cream of tartar (if using) on medium-high speed in a stand mixer fitted with the whisk attachment for about 2 minutes or with a handheld mixer for about 3 minutes, or until medium peaks form. Add the remaining granulated sugar, and beat on high speed for 1 to 5 minutes longer (depending on what kind of mixer you are using), until stiff peaks form. Mix one-fourth of the egg white mixture into the almond mixture until smooth, to lighten the mixture.

4

Using a rubber spatula, fold this mixture with the remaining egg white mixture. Transfer the batter to the cake pans or sheet pans. If you are using sheet pans, spread the batter with an offset spatula and run your thumb around the edges to make a small moat to keep the edges of the cakes from sticking to the pans.

5

Bake round cakes for about 25 minutes, or until they bounce back to the touch. Bake sheet cakes for about 15 minutes, or until firm and they bounce back to the touch.

6

If you are baking sheet cakes, sprinkle 2 sheets of parchment paper as large as the sheet pan with confectioners’ sugar.

7

Run a knife around the edges of the cakes to make it easier to get them out of the sheet pans.

8

Quickly flip out the cakes over the parchment paper as soon as they come out of the oven by placing the cakes right next to the parchment. Peel away the cooked parchment from the bottoms of the cakes. Cut the cakes into rounds or rectangles and layer them with the same fillings you’d use for a sponge cake.

9

If you are baking round cakes, let them cool for 5 minutes in the cake pans and then turn out onto cake racks.