Creating Espresso Martini Cupcakes is simple and rewarding. Follow these steps for delicious results:

1. Preheat Oven: Preheat your oven to 350°F (175°C) and line a muffin tin with cupcake liners.
2. Mix Dry Ingredients: In a large bowl, whisk together the flour, sugar, cocoa powder, baking powder, baking soda, and salt.
3. Cream Butter: In another bowl, cream the softened butter until smooth. Add the eggs one at a time, mixing well after each addition.
4. Combine Wet Ingredients: Stir in the brewed espresso, coffee liqueur, and vanilla extract until fully combined.
5. Combine Mixtures: Gradually add the dry ingredients to the wet mixture, stirring until just combined. Be careful not to overmix.
6. Divide Batter: Evenly distribute the batter into the prepared cupcake liners, filling each about two-thirds full.
7. Bake: Place in the preheated oven and bake for 20-25 minutes, or until a toothpick inserted into the center comes out clean.
8. Cool: Remove from the oven and let the cupcakes cool in the tin for about 10 minutes, then transfer them to a wire rack to cool completely.
9. Prepare Frosting: While the cupcakes cool, make the espresso buttercream. In a mixing bowl, beat the softened butter until creamy, then gradually add the powdered sugar, espresso, and vanilla extract. Beat until smooth and fluffy.
10. Frost Cupcakes: Once the cupcakes are completely cool, generously frost them with the espresso buttercream using a piping bag or knife.
11. Garnish: Top each cupcake with a coffee bean for an elegant finish.