Step 1

Preheat oven to 375 F/190 C.

Step 2

in a small saucepan, heat butter on low to medium heat, occasionally swirling the pan over the stovetop for about 5 minutes. It will foam at first, but then it will begin to brown, producing dark golden flecks (browned milk solids). Check the color and once you are happy with the level of browning, pour the butter (with milk solids) in a bowl to stop cooking. Let it stand and fully cool down.

Step 3

using an electric mixer whisk egg whites for no longer than 20 seconds and set aside. In a separate bowl, combine sugar, all-purpose flour, almond, and hazelnut flour. Add beaten egg whites to the dry ingredients and mix with a hand whisk. Stir in the brown butter.

Step 4

Generously butter cavities of a mini muffin pan. Pour the batter into the mold filling the holes up to two-thirds. Bake for 15 to 17 minutes, until nicely browned. Remove from the oven, and let cakes cool before removing them from the mold.