Prep the pan and oven: Line a 24-cup mini muffin pan with paper liners. Preheat your oven to 350°F (175°C).

Mix dry ingredients: In a medium bowl, whisk the flour, sugar, baking powder, and salt until evenly combined.

Combine wet ingredients: In a separate bowl, whisk the melted butter, milk, eggs, and vanilla until smooth. Make sure the butter is not hot, or it may scramble the eggs.

Make the batter: Pour the wet ingredients into the dry. Stir gently with a spatula just until combined. The batter should be smooth but don’t overmix. Fold in optional add-ins if using.

Fill the liners: Use a small cookie scoop or spoon to fill each liner about 3/4 full. This helps them rise into a nice dome without overflowing.

Bake: Bake for 10–12 minutes, or until the tops spring back lightly when touched and a toothpick comes out clean. Mini cupcakes bake fast, so start checking at 9 minutes.

Cool: Let them cool in the pan for 2–3 minutes, then transfer to a wire rack to cool completely before frosting. Warm cupcakes will melt your frosting.

Make the frosting: Beat the softened butter on medium speed until creamy, about 2 minutes. Add powdered sugar, vanilla, and salt. Beat on low until incorporated, then increase to medium-high until fluffy, 1–2 minutes. Add milk or cream a little at a time until it’s smooth and pipeable.

Frost and decorate: Transfer frosting to a piping bag fitted with a small star tip, or spread with a knife. Add sprinkles, mini chips, toasted coconut, or a drizzle of chocolate.

Serve: Arrange on a platter or tiered stand. They’re best the same day but hold up well for a day or two.