- 2 cups MINUS 2 tbsp superfine brown rice flour (plus more for dusting the cake pans)
- 1 cup buttermilk, full fat, at room temperature
- 5 whole eggs, separated, at room temperature
- 2 egg whites, at room temperature
- 2 1/4 cups sugar, divided
- ¾ cup butter, at room temperature
- ¾ cup shortening
- 1 tbs pure vanilla extract
- ½ tsp lemon extract (optional)
- 1/2 cup potato starch
- 1/4 cup tapioca flour
- 3 tsp Xanthan gum
- 2 tsp baking powder
- 1 tsp salt
- 1/4 tsp nutmeg
- Whisk the superfine brown rice flour and buttermilk together in a medium size bowl until smooth. Set aside.
- Heat oven to 325. Using superfine brown rice flour and butter or shortening, grease and flour three 8 or 9-inch round cake pans, and line the bottoms with a round of parchment paper that is also slathered with a bit of butter or shortening.
- Separate the 5 whole eggs, placing the 5 yolks in a small bowl and the whites in a separate medium
size bowl. Add the 2 additional egg whites so that you have a total of 7 egg whites. Using an electric mixer, beat the egg whites until frothy. Slowly pour in 1/4 cup of the sugar, beating as you pour. Continue to beat until the meringue is glossy and stiff peaks form when you lift the whisk from the beaten egg whites. Set aside.
- Fit the standing mixer with the whisk attachment and cream the butter, shortening, and remaining 2 cups of sugar until very light and fluffy, about 6 minutes. Stop the mixer to scrape down the sides of the bowl a time or two. Beat in the vanilla and lemon extracts until well combined.
- Add the egg yolks one at a time, beating each until fully incorporated, about 20 seconds, before adding another. Stop to scrape down the sides of the bowl from time to time.
- Add the potato starch, tapioca flour, Xanthan gum, baking powder, salt, and nutmeg to a medium bowl and mix with a wire whisk to combine.
- Add the buttermilk and rice flour mixture to the stand mixer bowl along with the dry ingredients. Beat on medium-high speed for about 60 seconds, until the batter is completely smooth.
- With a rubber spatula, gently fold the beaten egg whites into the batter just until incorporated. Be gentle – you want to retain as much air in the batter as possible.
- Divide the batter evenly between the prepared pans. Bake for 40-50 minutes. When done, the cakes will be golden brown and pulling away from the sides of the pan. To check for doneness, stick a toothpick into the center of one of the layers. Remove the toothpick and look for signs of raw batter. If only cake crumbs stick to the toothpick, the cake is done. You can also scoop a tiny amount of cake from the center of one of the layers to check for doneness. (You’ll be covering the cake with frosting anyway.)
- Let the cakes cool on wire racks for 5 minutes in the pan, then gently turn them out of the pans onto the wire racks to cool completely. If you don’t plan on frosting the layers immediately, wrap each tightly with plastic wrap. The layers can be stored at room temperature for 1 day, or frozen for up to 2 months.
- Frost with Vanilla Italian Meringue Buttercream, or your favorite icing recipe.
Keywords: cake, gluten free, gluten free cake, vanilla cake, white cake, layer cake