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

Sift together the all-purpose flour, unsweetened cocoa powder, baking powder, baking soda, and salt.

Mix the hot brewed coffee, milk, and melted unsalted butter together until smooth. Then add granulated sugar, eggs, and vanilla extract.

Gently fold the dry ingredients into the wet mixture until smooth with small lumps.

Scoop the batter into the lined muffin tin, filling each liner about two-thirds full, and bake for 16–18 minutes.

Remove the cupcakes from the oven and cool in the pan for 5 minutes, then transfer to a wire rack.

Whip the heavy cream and instant coffee granules until soft peaks form, then add powdered sugar and cream cheese until thick and creamy.

Beat together the softened unsalted butter, then add powdered sugar and cocoa powder, followed by brewed coffee and vanilla extract.

Fill each cooled cupcake with the coffee filling and frost with the chocolate buttercream.

Melt dark and white chocolate separately for drizzle and decorate the frosted cupcakes.