Heat your oven to 350°F and line a standard muffin tin with paper liners—I use the thicker ones because they hold their shape better and look prettier when people peel them back. Whisk together flour, baking powder, and salt in a small bowl, setting this dry mixture aside while you work on the butter and sugar base.
Cream together softened butter and sugar until the mixture looks pale and fluffy, which takes about three minutes with an electric mixer. I confess I used to skip this step thinking it wouldn't matter, until Jake pointed out my cupcakes looked "too flat and sad"—he was right, and now I never rush past it because creaming creates the air pockets that give you that tender crumb.
Add eggs one at a time, beating well after each addition so the mixture stays smooth and emulsified. Pour in the milk and vanilla bean paste, stirring gently until everything combines into a silky base that coats the back of a spoon. The why: this wet base needs to be fully combined before you introduce flour or you'll end up with streaks and uneven texture throughout your 4th of july cupcakes cozy recipe.
Fold in the dry ingredients with a spatula using about twelve strokes—don't overmix or your cupcakes will feel tough and tight instead of tender. Divide the batter evenly between three small bowls, leaving one portion plain while you add red gel coloring to the second bowl and blue gel coloring to the third, stirring each until the color deepens uniformly.
Working quickly, layer the batter into lined cups by spooning about one teaspoon of one color, then one teaspoon of a different color, alternating until each liner is three-quarters full. The layers won't blend together if you work fast—this is where I learned that hesitation ruins the whole effect, so trust your speed here and don't second-guess the colors.
Bake for 18-20 minutes until a toothpick inserted into the center comes out clean and the tops spring back when you press them gently with one finger. I time this carefully because even two extra minutes can turn these from moist and tender to slightly dry on the edges—the difference between "I'll have another" and "these are just okay."
Cool in the pan for five minutes, then transfer to a wire rack to cool completely before frosting, which takes about forty minutes. Resist the urge to frost warm cupcakes because the frosting will melt right off and make a mess—room temperature cupcakes hold the frosting in those perfect, defined swirls.
Frost each cooled cupcake with cream cheese frosting using an offset spatula or the back of a spoon, then top with sprinkles before the frosting sets completely so they stick.