This '70s-era treat features a topping of marshmallow, chocolate ganache, and pecans atop a rich, dense-dark chocolate cake.

Cake
1 cup (2 sticks, 8 ounces) butter
1/3 cup (1 ounce) Dutch-process cocoa
1 cup (8 ounces) hot water
2 cups (8 1/2 ounces) King Arthur Unbleached All-Purpose Flour
2 cups (14 ounces) granulated sugar
1 teaspoon baking soda
1/2 teaspoon salt
1 teaspoon espresso powder
1/2 cup (4 ounces) sour cream
2 large eggs
1 teaspoon vanilla

Topping
2 cups (11 ounces) Marshmallow Fluff or marshmallow crème
1 cup (6 ounces) semisweet chocolate chips or chopped semisweet or bittersweet chocolate
1/2 cup (4 ounces) heavy cream
1 cup diced, toasted pecans
1 cup toasted coconut, optional

Substitite our Hot Fudge Sauce Mix, prepared as directed; or Dark Chocolate Delight Fudge Sauce for the chopped chocolate and cream, if desired.

Cake: Preheat the oven to 350°F. Grease and flour a 9" x 13" cake pan, or our 2-quart casserole pan.

Melt the butter, then stir in the cocoa and hot water. In a separate bowl, combine the flour, sugar, soda, salt, and espresso powder. Pour the cocoa mixture over the dry ingredients, stirring to blend; the mixture will be a bit lumpy. Add the sour cream, eggs, and vanilla, beating till nearly smooth; a few small lumps may remain.

Pour the batter into the prepared pan. Bake the cake for 30 to 45 minutes (longer for the casserole pan), or until a tester inserted into the center comes out clean. Remove the cake from the oven. Wait 1 minute, then spoon on the marshmallow; wait another 2 minutes, and gently spread the marshmallow over the surface of the cake. Allow it to cool to lukewarm, at least 1 hour.

Combine the chocolate and cream in a microwave-safe bowl, and heat for 60 to 90 seconds, until the cream is very hot. Stir until the chocolate melts, and keep stirring till the mixture becomes smooth. Note: Substitute 3/4 to 1 cup chocolate sauce for this ganache, if desired; our Dark Chocolate Delight sauce is perfect. Drizzle over the cake. Top with the diced nuts (and coconut, if desired). Yield: 1 rich cake, about 3 dozen servings.