The Ultimate Kit Kat Birthday Cake Featuring My Favorite Chocolate Cake Recipe

I've been working for years to perfect my signature chocolate cake recipe -- a cake that is moist, deeply chocolatey, and can be stacked umpteen layers high.  The batter is versatile -- baking up perfectly peaked cupcakes or easy to level layers.  The best part is, it hardly takes more time to throw together than a mix! 

When you have the perfect recipe, it's easy to get creative with all the possibilities for complimentary fillings, frostings and decorations.  This week my youngest daughter turned eight.  She's a huge fan of Kit Kat bars, so when she asked that I bake her a chocolate cake, I knew exactly what I'd make for the birthday girl.

 

This towering chocolate confection feeds 10, generously.  It consists of 6 layers of decadent sour cream chocolate cake, homemade chocolate frosting, and lots of Kit Kat bars.

Kit Kat Cake

(makes one 6" cake, serves 10 with large pieces, or 20 with small pieces)

1 batch Flour Shop Signature Chocolate Cake (recipe below)

(will make three 6" rounds, plus 12 cupcakes)*

1 batch Perfect Chocolate Frosting (recipe below)

40 Snack Size Kit Kat bars (for a total of 80 individual sticks)

1 6" cardboard round or cake board

Step 1:  Unwrap the Kit Kat bars and divide into individual sticks.  You will need 60 nice looking pieces to adorn the cake.  Chop up the remaining pieces.  Set aside.

Step 2: Using a cake leveler or sharp knife, remove the rounded tops from all three 6" cakes.  Then, divide each cake into two equal layers.  Set all 6 layers aside. Each cake will yield a "top piece" which has two cut surfaces, and a "bottom piece" which has one cut surface and one smooth surface (the part that touched the bottom of the pan while baking).

Step 3:   Spread a thin layer of chocolate frosting on the cake board. Place one layer (a "bottom piece") of cake evenly on top of the board (cut side up).  Spread with a thin layer of frosting.  Add the next layer (a "top piece").  Spread with a thin layer of frosting.  Follow with another "top piece" of cake.  Spread with a thin layer of frosting.  Sprinkle frosting with some chopped Kit Kat pieces.  

Tip:  I like to assemble the layers on a cake turntable or lazy Susan, to make the process of frosting easier. 

Step 4:  Spread a thin layer of frosting on the smooth side of a "bottom piece" of cake.  Place on top of the Kit Kat layer.  Continue to alternate cake layers and frosting, ending with a "bottom piece", cut side down, so that the top of the cake is smooth.

Step 5:  Frost the entire cake.  The outer frosting (as well as the layers in-between)  should be thin.  Because the cake is so high, thick frosting in-between layers can lead to instability and can throw off the ratio of cake-to-frosting, disrupting the balance of flavors.  The outer frosting should be thin for the same reason of flavor, but also so the Kit Kat bars have a firm surface on which to stick.

Step 6:   Transfer cake to a serving plate.  It's easier to decorate on the final plate, rather than decorating, then transferring.  Begin decorating by setting one Kit Kat stick in place, vertically, with the bottom off the stick flush with the bottom of the plate.  Continue by adding remaining sticks (30 in all) as tightly together as possible.  The final piece may take a bit of gently wiggling to set in place, but it makes for a nice tight fit and perfect alignment.  Repeat process with second layer, lining up the first piece with one of the Kit Kat sticks in the bottom row. 

Step 7:  To finish cake, sprinkle remaining Kit Kat pieces on top.  Chill for at least an hour, then serve.  This cake is so easy to portion:  "Would you like a one-stick piece, 2-stick piece, or 3?"

You can see how easy it would be to divide these slices in two (three Kit Kats and layers of cake per guest) -- yielding 20 servings from this cake.  

Flour Shop Signature Chocolate Cake

(makes three 6" round cakes for this recipe, plus 12 cupcakes)

(Will also make two 9" rounds or 3 dozen cupcakes)

 

1 Tablespoon butter
1 1/2 cups unsweetened cocoa powder, plus more for dusting
3 cups all purpose flour
1 Tablespoon baking soda
1 teaspoon Kosher salt
1 1/2 teaspoons baking powder
3 cups granulated sugar
3/4 cups vegetable oil
1 cup regular sour cream
1/2 cup lowfat milk
1 1/2 teaspoons vanilla extract
3 large eggs (use the freshest eggs possible to ensure the best leavening)
1 1/2 cups hot coffee

1. Preheat oven to 350.  Use the 1TB butter to grease 3 6" cake pans with straight sides.  Line each pan with a round of parchment paper, then butter the paper.  Dust inside of pans with some cocoa powder.  Set aside.


2. In the bowl of a standing mixer, add dry ingredients.  Stir on low for 1 minute to aerate and combine.


3. Beat in remaining ingredients one at a time on low.  Increase speed to medium and beat until smooth (about 2 minutes).


4. Fill each pan 2/3 full.  Remaining batter can be divided in a lined cupcake pan.  Bake cupcake on upper middle-rack for 25-30 minutes.  Cakes should be baked for 35-45 minutes, or until a toothpick inserted in center of a cake comes out clean.  Remove from oven and cool for 15 minutes.


5. When pans are cool enough to handle, flip cakes out of pan, then back over to continue cooling on a wire rack.  When cakes have reached room temperature, wrap in plastic and refrigerate until ready to use.

Foolproof Chocolate Frosting

(based on the Cook's Illustrated recipe of the same name)

2 1/2 sticks unsalted butter, softened
1 cup confectioners' sugar
3/4 cup unsweetened cocoa powder
1/2 teaspoon kosher salt 
3/4 cup light corn syrup
1 teaspoon vanilla extract
4 ounces high quality semi-sweet chocolate chips
4 ounces high quality milk-chocolate chips

1. In a microwave safe bowl, or double-boiler, melt semi-sweet and milk chocolate chips together.  set aside.


2. In the bowl of a food processor, process butter, sugar, cocoa and salt until smooth.  


3. Scrape down sides, then add corn syrup (this gives the frosting it's luscious gloss) and vanilla and process until just combined. 


4. Scrape sides of bowl, then add melted chocolate.  Pulse until smooth and creamy.  


5. Frosting is ready to use. 

* Cutting the recipe in half would have yielded too little cake, so I decided to go with a full batch.  It gave me the 3 6" cakes needed for this recipe, plus a dozen cupcakes.  There's enough frosting left to top the cupcakes as well.  I always like to have a few treats on hand for friends who stop by and to bring to work.  Perfect!