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

Combine cooled brewed coffee and coffee liqueur in a medium bowl and mix well.

Whisk together flour, baking powder, and salt in a separate mixing bowl.

Cream together butter and sugar in a large bowl until light and fluffy.

Incorporate eggs one at a time, then add vanilla extract and mix until smooth.

Gradually add dry ingredients to the wet mixture, alternating with whole milk, and mix until just combined.

Fill cupcake liners two-thirds full with batter and bake for 18-20 minutes.

Allow cupcakes to cool in the pan for 5 minutes, then transfer to a wire rack to cool completely.

Beat together mascarpone cheese and heavy cream until soft peaks form, then add powdered sugar and beat until stiff peaks form.

Dip the tops of each cooled cupcake into the coffee mixture, soaking them gently.

Layer the mascarpone frosting generously on each cupcake, creating swirls.

Dust the frosting with cocoa powder before serving.