Preheat the oven to 350°F. Line 24 cupcake sections with liners and set aside.
In a medium-sized bowl, stir together the flour, cocoa powder, baking powder, and salt.
In a large bowl, whisk together the sugar, milk, oil, eggs, and vanilla until smooth.
Add the flour mixture to the wet and whisk until combined.
Add the Bailey’s and stir until smooth, scraping the sides as needed.
Fill cupcake liners with 3 tablespoons of batter each; you may have a little batter left over, but that’s okay.
Bake for 18-22 minutes until a toothpick inserted into the center comes out clean.
Allow the cupcakes to cool in the pan for 5 minutes. Then, take them out and place them on a wire rack.
Immediately start poking holes all over the cupcakes with a toothpick.
Brush the tops with the additional Bailey’s for the soak. Allow to cool completely.