Step 1

Preheat the oven to 350°F. Line a muffin tin with foil cupcake liners, and set aside.

Step 2

In a large mixing bowl, add melted butter and whisk in sugar until butter is no longer warm to the touch.

Step 3

Whisk in egg, buttermilk, and vanilla until well combined. Set aside.

Step 4

In a separate mixing bowl, add remaining cupcake ingredients, and quickly whisk together.

Step 5

Add dry ingredients to butter mixture, and whisk until combined.

Step 6

Scoop batter into prepared muffin tin, filling ¾ of the way up (you may need to do 2 batches or use another tin).

Step 7

Bake for 14-16 minutes at 350°F, until tops spring back lightly to the touch or a toothpick comes out clean.

Step 8

Remove cupcakes to a wire rack after 15 minutes. Allow cupcakes to finish cooling.

Step 9

Use a small skewer or fork to poke holes all over the top of the cupcakes. Set aside.

Step 10

In a medium mixing bowl, whisk together the three milks.

Step 11

Drizzle milk mixture slowly over the cupcakes, giving it enough time to absorb into the cupcakes before adding more.

Step 12

Cover cupcakes lightly and refrigerate for at least 1 hour or up to 12 hours.

Step 13

Chill a large metal mixing bowl for 15-20 minutes.

Step 14

Add heavy cream, vanilla, and powdered sugar. Beat until stiff peaks form (like whipped cream).

Step 15

Mix in mascarpone cheese, and whisk to combine.

Step 16

Spread or pipe frosting onto chilled cupcakes.