Makes one 9-inch cake

3/4 cup butter
1 cup sugar
3 eggs
1/2 cup milk
1 teaspoon vanilla
1 1/2 cups almond meal
1/2 cup coconut flour
2 teaspoons baking powder

Preheat your oven to 350° F. Grease a 9-inch round cake pan and line the bottom with parchment.
Cream together the butter and sugar until light and fluffy. Add the eggs (one at a time), mixing until incorporated. Add milk and vanilla and beat until incorporated.
In a separate bowl, whisk together the almond meal, coconut flour, and baking powder. Add the dry ingredients to the wet and mix thoroughly.
Pour the batter into your prepared pan and bake for 35 to 40 minutes. The cake should be golden brown and starting to pull away from the sides.
Let the cake cool in the pan for 10 minutes or so. Once cool (in the pan or out of the pan, either works), chill the cake in the refrigerator. It is VERY moist and needs to chill slightly to firm up. link