Place butter into small sauce pan on medium heat. Using a wire whisk continue to stir. Once you see large bubbles, increase to medium high heat. Continue to stir until you see an almost amber color. Remove to a bowl to cool.
Mix almond flour, tapioca flour, salt, swerve (or sugar) in bowl.
Make a hole in flour. Add egg whites.
Whisk together gently.
Add in butter and vanilla. Mix.
Spoon into the vessels of your choice.
Bake for approximately 13 minutes until golden brown.
That can be a mini muffin pan, financier pan, whoopie pie pan or mini tart pans.
You will get 12 mini muffins, etc. and six using mini tart pans.