Preheat oven to 350° Fahrenheit and line a cupcake pan with cupcake liners.
In a medium bowl, whisk together the gluten-free flour baking powder, baking soda, and salt.
In a large bowl, beat together the butter and sugar with either a hand or stand mixer until fluffy. Beat in one egg at a time, then add in the vanilla extract.
With your mixer on low speed, add 1/3 of the flour mixture into the butter mixture, then about half of the milk. Then, add in another 1/3 of the flour mixture, then the remaining milk, then the remaining flour mixture.
Once batter is fully combined, transfer ¼ cup of batter into each cupcake mold. Bake cupcakes for 18-20 minutes or until a toothpick inserted into the center of a cupcake comes out clean.
Remove cupcakes from oven and transfer to a wire rack to cool completely before frosting.
Make the frosting by adding all frosting ingredients to a large bowl and beating with either a hand or stand mixer until light and fluffy.
Once cupcakes have cooled, decorate with frosting and sprinkles if you’d like.