Preheat your oven to 350°F, line a muffin pan with paper muffin cups and set aside.

Mix your dry ingredients (all-purpose flour, baking soda, baking powder, and salt) in a mixing bowl and set aside.

In a standing mixer, using a paddle attachment, beat together butter and granulated sugar for about 5 minutes until pale and fluffy.

When ready, add eggs, vanilla extract, and buttermilk. Mix well until all the ingredients are well incorporated.

Add dry ingredients, and using a spatula, fold it in.

Add sprinkles and fold it in until evenly distributed.

Divide the mixture between 12 muffin cups and bake at 350°F for about 20 minutes.

In a standing mixer, using a paddle attachment, beat together unsalted butter and powdered sugar on high speed for 5-7 minutes until light and airy.

Add vanilla extract and heavy cream and beat again for 3-5 minutes until the right consistency.

To decorate the cupcakes, scoop the buttercream frosting into a piping bag with 1 mm open star piping tip and pipe it over the cupcakes.

Decorate with additional sprinkles.