• Preheat the oven to 350 degrees F. Grease an 8×8 inch pan with butter and set aside. In a measuring cup, whisk the hot coffee and butter until the butter melts, then set it aside until ready to use.
• In a large bowl, whisk together the eggs, buttermilk, whiskey and vanilla extract. Stir in the sugar, flour, cocoa, baking powder, soda and salt. Once it’s about halfway mixed, pour in the coffee/butter mixture and stir until you have a smooth batter. Stir in the chopped chocolate. Pour the batter into the greased pan and bake for 25 to 30 minutes, or until the cake is just set in the middle. Let cool completely before frosting.

chocolate ganache frosting

• Place the chocolate in a bowl. Heat the heavy cream and irish cream in a small saucepan over low heat until it just bubbles around the edges. Pour the cream over the chocolate and let it sit for a minute, then stir continuously until the chocolate melts into the cream and comes together. Let sit for one hour at room temperature, then spread the ganache all over the cake. It will be THICK! Top with the marshmallows if desired. If you make the cake ahead of time (like the night before or morning of), add the marshmallows right before serving – in which case you may need to press them into the ganache so they hold. The marshmallows will stay crunchy for about 4 to 6 hours – after that they start to soften a bit.