2.) In a small saucepan, combine butter, cocoa powder, and Guinness. Heat over a medium flame until the butter melts.
3.) Put sugar, eggs, and buttermilk in a mixing bowl. Beat with an electric mixer until combined. Stir in the Guinness mixture.
4.) Sift in the flour and baking soda, whisking until combined. Pour batter into a greased 8" round pan; bake for 45 mins or until a knife stuck into the center comes out clean.
5.) While the cake is in the oven, make the chocolate ganache. Melt the butter and chocolate in a double boiler (you can easily improvise one). Let cool for 5 to 10 minutes.
6.) Finally, to assemble the cake: cut the cut in half, and fill with fresh whipped cream and fresh fruit of your choice. Place the other half of the cake on top, then pour over the ganache. Top with more fruit.