Put your egg whites in a bowl and let stand at room temp for at least 30 minutes. (Fresher eggs work best b/c they separate easier.)

Preheat oven to 325.

Sift powdered sugar, xanthan gum and cake/pastry flour together and set aside.

Combine egg whites, vanilla extract, and cream of tartar in a large bowl with a whisk on high speed.

Gradually add sugar to egg white mixture, beating continuously at medium speed. Beat until all sugar is dissolved and stiff peaks form.

Sift about 1/4 cup of flour mix to cover top of the foam and fold gently using a spatula. Continue adding about 1/4 cup at a time until all mixed in. *if you add flour all at once the cake will be flat and not airy & fluffy.

Carefully spoon 1/4 cup of mixture into a paper lined muffin cup.

Cut through each cupcake batter with a knife to help remove air pockets.

Bake for 25-35 minutes or until golden brown and toothpick comes out clean.

Cool completely before adding icing and toppings. I used store bought white whipped icing (gluten free) and strawberries to top my cupcakes.