Preheat your oven to 350°F (175°C) and line a muffin tin with cupcake liners. In a large bowl, whisk together flour, cocoa powder, baking powder, baking soda, and salt until combined.

In a separate bowl, mix hot coffee, milk, melted butter, sugar, eggs, and vanilla until smooth. Gradually combine wet and dry ingredients, stirring gently until just combined.

Divide batter among liners filling each about 2/3 full. Bake for 16-18 minutes, or until a toothpick comes out clean with a few moist crumbs. Cool in the pan for 5 minutes, then transfer to a wire rack.

In a chilled bowl, whisk heavy cream and instant coffee until soft peaks form. Gradually add powdered sugar and cream cheese, whipping until thick and creamy. Transfer to a piping bag.

Once cooled, cut a small well in the center of each cupcake, and pipe in the coffee cream filling generously.

Beat softened butter until creamy, then gradually add powdered sugar and cocoa powder. Mix in coffee and vanilla, beating until light and airy.

Pipe the chocolate buttercream on top of each cupcake, ensuring to cover the filled wells and create a decorative finish.

Melt dark and white chocolate separately, then drizzle dark chocolate over the frosted cupcakes in a zigzag pattern, adding white chocolate drizzles if desired.