Preheat your oven to 350°F (175°C). Line a standard muffin tin with cupcake liners.

In a large bowl, cream together 1 cup of softened unsalted butter and 1 cup of granulated sugar until light and fluffy, about 3 minutes.

Gradually add in 3 large eggs, one at a time, beating well after each addition. Then mix in 1 teaspoon of vanilla extract, 1 tablespoon of instant espresso powder, and ½ cup of brewed espresso until fully combined.

In a separate bowl, whisk together 1 ½ cups of all-purpose flour, ½ cup of unsweetened cocoa powder, 1 teaspoon of baking powder, ½ teaspoon of baking soda, and ½ teaspoon of salt.

Slowly add the dry ingredients to the wet mixture, gently folding together. Be careful not to overmix.

Fill each cupcake liner about two-thirds full with the batter and bake for 16-18 minutes.

Once baked, let cool in the pan for about 5 minutes before transferring to a wire rack to cool completely.

While the cupcakes cool, prepare the frosting by beating 1 cup of softened unsalted butter until smooth, then gradually adding 3-4 cups of powdered sugar, 2 tablespoons of instant espresso powder, and 2 tablespoons of brewed espresso.

Frost the cooled cupcakes with the espresso-infused frosting and garnish with cocoa powder or chocolate shavings.