Step 1

Place the butter in a small saucepan. Melt over medium heat. Continue cooking until butter is boiling and turns golden brown and smells nutty, about 8 minutes. Pour into a bowl and cool for 30 minutes.

Step 2

Preheat the oven to 350F. Grease the wells of a mini muffin pan by brushing them lightly with softened butter.

Step 3

In a large mixing bowl, whisk together the powdered sugar, almond flour, all-purpose flour, and salt. Add the egg whites, vanilla, and cooled browned butter. Whisk together until just combined. (The batter will be thick.)

Step 4

Divide the batter among the greased muffin pan cups. (I like to place the batter in a piping bag for easy filling!) They will be about three-quarters.

Step 5

Bake for 15 to 20 minutes or until the edges are golden brown and a toothpick inserted into the center comes out clean. Let cool in the pan for 10 minutes. Remove and cool completely on a wire rack.