Preheat oven to 350°F. Melt chocolate and butter in a double boiler. Whisk in sugar until fully incorporated. Cool chocolate mixture down to room temperature. In a standing mixer, whisk egg whites until stiff peaks form and gently fold into the chocolate.
Grease two spring form pans and divide the batter evenly. Place in the oven and bake for 35 minutes. When completely cooled, add frosting to the top of each cake and layer the cakes upon one another.
Chocolate Raspberry Butter Cream:
In a standup mixer whip butter, cocoa powder and confectioners sugar. Add raspberry jam and vanilla extract then mix well on high speed for 1 minute. Add milk as needed until you reach a desired consistency.
Goes perfectly with Guinness® Foreign Extra Stout