Preheat oven to 350°F. Line a 12-cup muffin pan with paper liners.
Whisk flour, baking powder, baking soda, and salt in a bowl.
Cream butter and sugar until pale and fluffy, about 2 minutes.
Beat in eggs one at a time. Mix in vanilla.
Add dry mix in thirds, alternating with buttermilk. Mix just until combined.
Fold in sprinkles gently to avoid color streaking.
Scoop batter into liners, filling each about two-thirds full.
Bake until tops spring back and edges lightly golden, about 18 minutes.
Cool in pan 5 minutes, then transfer to a rack to cool completely.
For frosting, beat butter until smooth and creamy.
Gradually beat in powdered sugar until light and fluffy.
Mix in vanilla, cream, and salt. Whip to a silky spreadable consistency.
Swirl frosting onto cooled cupcakes. Shower with extra sprinkles.
Notes
Try swapping 1 tsp vanilla in the frosting with 1/2 tsp almond extract for a bakery-style twist. Store cupcakes covered at room temperature for 1 day, or refrigerate up to 4 days; bring to room temp before serving.This recipe is an original creation inspired by classic Funfetti Cupcake Recipes flavors. All ingredient ratios and instructions are independently developed.