Banoffee Cupcakes

For the cupcakes:
Preheat oven to 350 F. Grease a 12-count muffin tin or line with muffin liners.

In a large bowl, mix together sugar, flour, cocoa powder, baking powder, baking soda and salt. Crack in the egg, spoon in the sour cream, and pour in the oil and the vanilla. Mix with a wooden spoon until just combined. Pour in the boiling water, and slowly mix until smooth.

Divide batter evenly among prepared muffin cups, filling each about halfway full. Transfer muffin tin to oven and bake for 15 to 18 minutes. Transfer muffin tin to a wire rack and let cupcakes cool completely.

To prepare for the assembly, place graham cracker crumbs in a small bowl, and whip heavy cream to stiff peaks. Smear a layer of Nutella on top of a cupcake. Dip cupcake into the graham cracker crumbs to coat the top, followed by a dollop of whipped cream. Insert a banana slice and a graham cracker cookie. Sprinkle with chocolate shavings and drizzle with dulce de leche. Repeat with the other cupcakes.