Old fashioned chocolate mayonnaise cake is moist and tender with BIG chocolate flavor. It's filled and frosted with the creamiest mocha buttercream ever - great for birthdays or Sunday dinners. Instructions for making layer cake or easy sheet cake are included.
4ouncesbittersweet chocolatehigh quality 70% cacao, chopped or chocolate chips
1cupdark unsweetened cocoa powderI used Hershey's Special extra dark
1 ¾cupsdark coffee or waterboiling
2 ⅔cupsall purpose flour
1 ¼teaspoonsbaking soda
¼teaspoonbaking powder
1cupsugar
1cupdark brown sugarpacked
1 ⅓cupsmayonnaise(I prefer Hellman's or Dukes to anything else....but do not use reduced-fat or fat-free)
2eggs
1egg yolk
1teaspoonvanilla extract
Fudge Frosting
2 ¼cupsbuttersoftened
1 ½cupsconfectioners' sugar
¾cupunsweetened dark cocoa powderI used Hershey's Special extra dark
½cupcoffeehot and double strength
½cupsour cream
1 ½teaspoonsvanilla extract
1pinchkosher salt
10ouncesdark chocolatechopped and melted
1tablespoonwhite corn syrup
Instructions
Cake
Preheat oven to 350°F
Grease three 8 -inch cake pans and dust with cocoa.
Melt the chocolate in the microwave just until softened and you can stir it smooth - about 1 minute.
Combine melted chocolate and cocoa in a bowl. Whisk in boiling coffee (or water) and stir until the mixture is smooth. Set aside.
Sift the flour, baking soda, baking powder, and salt into a bowl. Set aside.
With an electric mixer on medium-high speed beat the sugar and the mayonnaise until blended.
Add eggs one at a time, beating well after each. Add the egg yolk.
Beat in the vanilla.
Change to low speed. Add the dry ingredients in four additions, alternating with the chocolate mixture.
Beat well after each addition.
Divide cake batter evenly among the cake pans.
Bake about 30 minutes or until a cake tester comes out clean.
Cool cake for 10 minutes in pans.
Loosen cakes from sides of pans, turn out, and cool completely before frosting.
Frosting
In a bowl of stand mixer fitted with paddle attachment beat the butter on medium speed about 6 minutes or until pale and fluffy.
Sift together the confectioners' sugar and cocoa powder.
Reduce mixer speed to low.
Add the confectioners' sugar mixture, beating until well blended.
Continue beating on low and add the coffee, sour cream, vanilla, and salt.
Beat 1 minute.
Increase the speed to medium and whip for 2 minutes.
Add the melted chocolate and beat until smooth, about 2 minutes more.
For sheet cake
Follow instructions for mixing the batter.
Grease and flour a 13x9-inch baking dish.
Pour the batter in the baking dish and smooth top.
Bake for 30 to 35 minutes at 350°. Start checking for doneness at 25 minutes just to be on the safe side.
Cool completely in pan and frost with your favorite frosting.
Notes
Storage:Chocolate mayonnaise cake can be stored at room temperature in a cake holder or carefully covered with plastic wrap. It will be fine for up to 4 days or so.It freezes well for up to 4 months when stored in an airtight container.Tips:
Make sure all ingredients are at room temperature before you begin.
I dust my cake pans for chocolate cake with cocoa.
If you've had a problem with cakes sticking to the pans in the past then place a round of parchment paper in the bottom of the pans and grease it then dust with cocoa. The bottom will come loose without a problem and you can just peel the parchment paper off after it's done
Don't use reduced fat, olive oil, canola oil, fat free, or other mayonnaise variation. Use the old fashioned, full fat mayo - I suggest Hellman's.
Place a couple of thin dowels or straws through the stacked cake when you are frosting the sides and top - this will keep it from sliding around. Just remove them and smooth the top before serving.