Pre-heat the oven to 180C no fan. In a small bowl, sift the flour, sugar, cocoa powder, baking powder, baking soda, and salt together. In another bowl, mix the egg, milk, oil, and vanilla extract. Combine dry ingredients with wet one. Whisk until incorporated. Pour the hot coffee (or hot water) over the batter. Pour the batter into cupcake pan, filling 3/4 of the cup.

Bake in the pre-heated oven for about 18 minutes, or an inserted toothpick comes out clean. Remove from the oven and let the cupcakes cool while making Biscoff buttercream.

In a medium-sized bowl, beat butter and Biscoff spread together until fluffy and lightened in color, about 1 minute. Add powdered sugar and cocoa powder and using a rubber spatula, fold into the butter and Biscoff mixture. Once mostly incorporated, mix with the mixer until smooth. Add the cream and mix until the frosting is smooth and fluffy, about 1 minute.

To assemble: Remove the center of each cupcake. Place 1 tsp of cookie butter in the opened core of the cupcakes. Cover the top with the bit of cake you removed earlier. Pipe buttercream as you'd like. Enjoy!