4 eggs, separated
1/4 t salt
1-1/3 sticks unsalted butter, softened
3/4 C sugar
1-1/2 C rice flour
1/4 t vanilla

Preheat oven to 350 F. Grease a muffin tin (12 muffins).

Beat the egg whites with the salt until stiff. In another bowl, cream the butter and sugar, add the egg yolks, and stir until smooth. Stir in the rice flour and vanilla, then fold in the egg whites.

Spoon the batter into the muffin tin, filling them less than 3/4 full. Bake for 20 minutes, until puffed in the center and brown around the edges.

Let stand for 5 minutes to firm. Cool on a wire rack.