Preheat your oven to 350°F (175°C) and prepare two greased 9-inch round cake pans with parchment paper.

In a large bowl, whisk together all-purpose flour, baking powder, baking soda, salt, ground ginger, ground cinnamon, ground nutmeg, and ground cloves.

In a separate mixing bowl, cream unsalted butter until light and fluffy. Gradually add granulated sugar and brown sugar, mixing until airy.

Add eggs one at a time, blending well. Incorporate vanilla extract and molasses until smooth.

On low speed, alternate adding the flour mixture and buttermilk, mixing until just combined.

Divide the batter evenly between the pans and bake for 30-35 minutes or until a toothpick comes out clean.

Allow the cakes to cool in the pans for 5 minutes, then transfer to wire racks to cool completely.

Dissolve instant coffee in milk and set aside. Cream butter for buttercream and mix in powdered sugar before adding coffee mixture.

Level the cooled cake layers and cross each layer with a generous amount of buttercream, then chill for 30 minutes.

Frost the cake with remaining buttercream, drizzle with ganache, and decorate with marshmallows and sprinkles.