Preheat your oven to 350°F (175°C) and line a cupcake pan with liners.

Mix the dry ingredients in a bowl: flour, cocoa powder, baking powder, and salt. Whisk them together until combined.

Cream the butter and sugar together in a large mixing bowl until light and fluffy—about 3-5 minutes.

Add the eggs one at a time, mixing well after each addition. Then, pour in the vanilla extract and Irish cream liqueur.

Combine the wet and dry ingredients gradually, alternating with milk. Mix until just combined.

Spoon the batter into the prepared cupcake liners, filling each about two-thirds full. Bake for 18-20 minutes or until a toothpick comes out clean.

Cool the cupcakes in the pan for 5 minutes before transferring them to a wire rack to cool completely.