Preheat Oven: Preheat your oven to 350°F (175°C) and spray two baking pans with non-stick spray.

Cream Butter and Sugar: In a large mixing bowl, beat the softened butter and white sugar together with a mixer until creamy.

Add Egg and Vanilla: Add the egg and vanilla to the bowl and blend briefly.

Combine Dry Ingredients: Add the gluten-free flour, baking soda, and salt to the same bowl. Mix until a thick, smooth cookie dough forms.

Scoop Dough: Using a medium cookie scoop, place scoops of dough onto the prepared pans, spacing them evenly apart.

Bake: Bake in the oven for 9-12 minutes, or until the edges are crisp and the inside is slightly underdone.

Cool Cookies: Allow the cookies to cool completely before frosting.

Combine Ingredients: In a mixing bowl, add the softened butter, powdered sugar, and 1 tablespoon of milk.

Beat Until Creamy: Beat the mixture with a mixer on low speed until creamy. Add another tablespoon of milk if needed to reach the desired consistency.

Frost the Cookies: Once the cookies are completely cool, spread or pipe the buttercream frosting onto them. Decorate with food colors and sprinkles if desired.