Preheat oven to 350°. Line a 12-count muffin pan with 12 cupcake liners. Set aside.

In a medium bowl, mix together flour, baking powder, baking soda, and salt. Set aside. In a large microwave-safe bowl, melt butter in the microwave. Whisk in sugar—mixture will be gritty. Chill in the refrigerator for 1 minute. Stir in egg, yogurt, milk, and vanilla extract until combined. Slowly mix in dry ingredients until no lumps remain. Batter will be thick. Slowly stir in sprinkles, but do not overmix because the sprinkles will bleed their color.

Divide batter among 12 cupcake liners and bake for up to 20 minutes or until a toothpick inserted in the center comes out clean. Allow to cool.

In a medium bowl, beat the softened butter on medium speed with an electric handheld or stand mixer fitted with a paddle attachment. Beat for about 3 minutes until smooth and creamy. Turn mixer off and add confectioners’ sugar, cream, and vanilla extract. Mix on low for 1 minute then increase to high speed and beat for 3-4 full minutes. Add more powdered sugar if frosting is too thin or more cream if frosting is too thick. Add salt if frosting is too sweet (I usually add ¼ tsp). Frost cooled cupcakes and top with sprinkles.

Store cupcakes in an airtight container at room temperature for up to 3 days and in the refrigerator up to 5. I recommend a cupcake carrier for storing and transporting decorated cupcakes.