In a small bowl set over a pot of simmering water, or a double boiler, combine chocolate, butter, sugar and Baker’s Brew Coffee Spice. Stir until chocolate has melted and mixture is smooth. Stir in Guinness and whisk in egg yolks. Remove from heat. In a small bowl, whip cream with an electric mixer until soft peaks form. Fold whipped cream into chocolate mixture. With clean beaters in a medium bowl, beat egg whites with an electric mixer until stiff peaks form. Fold whipped egg whites into chocolate-cream mixture. Fill wine or shot glasses, parfait bowls or ramekins with mousse and refrigerate until set.
Serve topped with whipped cream and/or a light dusting of Baker’s Brew Coffee Spice.