Recipe from Sweet Tooth
1-1/2 tsp baking powder
1/4 tsp salt
3/4 cup sugar
6 tbsp unsalted butter, at room temperature
1 large egg + 1 egg white, at room temperature
1 tsp vanilla extract
1/2 cup whole milk
2 tbsp rainbow sprinkles (I used nonpareils)
I halved the recipe and was still able to frost most of the cupcakes.
I frosted the cupcakes with a 1M Wilson tip. I also accidentally added the milk into the frosting all at once, so my frosting wasn't as defined.