Deep Dark Secret Chocolate Cake (triple- or double-decker)

The secret?  I'll just tell you right now the first one - it's mayonnaise.  Original recipe from Bon Appetit April 2010: Chocolate Mayonnaise Cake for a birthday cake at the end of summer.  I'm not a great cake-eater, except for spice or carrot cakes.  Usually they're too dry, too boring, but this cake?  Amazing.  Moist and rich without feeling heavy.  Not oversweet, so that the real chocolate taste sings through.  

Of course, we further tweaked and adjusted (because we can't help ourselves) and suggest that SALTED butter in the frosting tips the balance just that much further into perfection.  You may consider adding a teaspoon or two of cinnamon to the batter along with the flour if you crave that Mexican chocolate deliciousness.

Deep Dark Secret Chocolate Cake
THE CAKE

Preheat oven to 350°F. Butter and flour three 8-inch-diameter cake pans with 1 1/2-inch-high sides.

Combine in medium metal bowl:

• 2 ounces bittersweet chocolate (do not exceed 61% cacao), chopped 
• ⅔ cup unsweetened cocoa powder

then add:

• 1¾  cups boiling water

and whisk until chocolate is melted and mixture is smooth.

Sift together in another medium bowl:

• 2¾  cups all purpose flour
• 1¼ teaspoons baking soda
• ¼ teaspoon baking powder
• 1-2 teaspoons cinnamon (optional) 

Beat in a large bowl until well blended (2 to 3 minutes):

• 1 cup sugar
• 1 cup (packed) dark brown sugar
• 1⅓ cups mayonnaise (do not use reduced-fat or fat-free)

then add, one at a time, beating until well blended after each addition:

• 2 large eggs

Beat in:

• 1 teaspoon vanilla extract

Add flour mixture to sugars in 4 additions,  alternating with chocolate mixture in 3 additions, beating until blended after each addition and occasionally scraping down sides of bowl.

Divide batter among prepared cake pans (about 2⅓ cups for each).

Bake cakes until toothpick inserted into center comes out clean, 30 to 32 minutes. Cool cakes in pans on racks 20 minutes.

Run small knife around sides of cakes to loosen. Carefully invert cakes onto racks and let cool completely.



THE FROSTING

Set in a medium metal bowl, over a saucepan of simmering water

• 10 ounces bittersweet chocolate (do not exceed 61% cacao), chopped

and stir until chocolate is melted and smooth. Carefully remove bowl from over water; let melted chocolate cool until lukewarm, stirring occasionally.

Beat in large bowl

• 1½  cups (3 sticks) salted butter, room temperature

until smooth and creamy.

Sift over the butter

• 3 cups powdered sugar

and beat until well blended, about 2 minutes.

Beat in

• 1 tablespoon vanilla extract

Add melted chocolate to the butter mixture and beat until well blended and smooth, occasionally scraping down sides of bowl.

TO FROST: Place 1 cake layer on platter. Spread ¾ cup frosting over top of cake layer to edges. Top with second cake layer; spread ¾ cup frosting over. Top with third cake layer. Spread remaining frosting decoratively over top and sides of cake.

~ OR ALTERNATIVELY - Frost one layer to take to a lucky neighbor, and enjoy the still generous double layer cake with plenty of family and friends at home.