Chocolate. Peanut butter. Cake. Need I say more? I am not much of a peanut butter lover (please don’t stop reading because of my indiscretion) but when it is paired with rich, decedent chocolate there is something sublime about it. When it is combined then in cake form with silky frosting and in mini-tower form I just cannot speak ill. Oh, and then there is the frosting. Let me just warn you I may have gotten carried away taking pictures during the steps of the frosting.
This cake and frosting is adapted from the Mile High Chocolate cake from Epicurious. It is moist, super chocolaty and the perfect partner to the strong flavor of peanut butter. It comes together quickly and bakes even faster when done in a sheet pan as I did. There are four sizes of sheet pans: full, two-thirds, half and quarter. I have half sheet pans because they are perfect size for almost anything you are using them for and easy to store in a small kitchen. After you make the batter you bake and then cool the cakes. You don’t even have to worry about flipping them out of the pans, which is always a high anxiety moment for me because I fear I will break it in half.
The second step of these adorable little cakes is the peanut butter filling. Whip all the ingredients in a bowl and you are done. The cream cheese gives the filling a nice lightness and the maple syrup that not only adds an element of sweetness but a wonderful depth of flavor.
Third part (my favorite part) is this frosting. This frosting blew my mind. It is a boiled frosting – yes, boiled. For a hardcore Swiss and Italian Meringue Buttercream girl this was definitely a new way of doing things.
So, you take sugar, chocolate, chocolate powder, salt, milk and flour (yes, flour) and boil it into a thick almost ganache like bubbly goodness and then let it cool on a plate.
While it is cooling you whip the butter until it is pale and creamy. You want it to look like whipped cream.
Once the butter is whipped and the chocolate mixture is cool you slowly add it and beat it until it is combined. What you end up with is this fluffy, smooth frosting that looks like chocolate mousse.
To assemble these little towers I just alternated cake and peanut butter filling. It started to lean so I decided I had better quit before it ended up on the floor. At that point I had already overfilled my piping bag once and had frosting all over myself and the counter so I decided to quit before things got worse. The cake is very tender so I decided to pipe the filling instead of spreading it with a knife. If you don’t have piping bags you can cut the tip off a plastic baggie and get the same result. Another thing I did when frosting the cake was put a “crumb coat” on it and then let it harden in the refrigerator for about 10 minutes. A crumb coat helps the cake stay together when you are frosting it so you do not rip and destroy it. I have never been great at frosting cakes. When I saw someone do this it changed the way I approached the once burdensome frosting of the cake.
If you want smooth sides the best way to get it is with an offset spatula and a cup of hot water. Dip the spatula in and then shake off the excess water. Place it flat against the frosted cake and twirl the plate around. Re-dip and shake as needed. To top it off I decided it needed a little color and the giant jar of sprinkles I have were the obvious choice. I may have smashed the side of it when I cut it….it really is a little leaning tower of cake!
Let me know how yours turned out! Post questions and comments below.
Ingredients for the Cake:
– 5 ounces (145 grams) good-quality dark or extra dark (semisweet or bittersweet) chocolate, chopped (I used Ghirardelli 60% chocolate chips.)
– 2 1/4 sticks (260 grams) unsalted butter, softened
– 2 3/4 cups (315 grams) cake flour (not self-rising), sifted
– 1/4 cup (24 grams) unsweetened cocoa powder (not Dutch-process. I use Ghirardelli Unsweetened Cocoa Powder.)
– 1 teaspoon (5 grams) baking powder
– 1/2 teaspoon (4 grams) salt
– 4 large eggs, at room temperature at least 30 minutes
– 1 cup (200 grams) granulated sugar
– 1 cup (220 grams) packed light brown sugar
– 1 1/2 tsp. vanilla extract (Don’t use the imitation kind!)
– 2 cups (475 mL) sour cream
Ingredients for the frosting:
– 1 cup (200 grams) granulated sugar
– 6 tablespoons (47 grams) all-purpose flour
– 6 tablespoons (36 grams) unsweetened cocoa powder (the same type you used in the cake)
– 1 1/2 cups (360 mL) whole milk
– 4 ounces (115 grams) good quality chocolate (the same type of chocolate you used for the cake)
– 1 Tbsp. vanilla extract
– 6 sticks (680 grams) unsalted butter, at room temperature
– Small pinch of salt
Ingredients for the filling:
– 8 oz. cream cheese, at room temperature
– ½ cup peanut butter
– 3 tbsp unsalted butter, at room temperature
– 4 Tbsp. maple syrup
– 1 tsp. vanilla extract
– Small pinch of salt
Directions for the cake:
-Preheat oven to 350°F with rack in middle. Butter two half sized sheet pans, line with parchment and then butter again. Then dust with flour, covering all sides and knocking out the excess.
-Melt chocolate with butter, then cool. I did it in the microwave in a glass bowl. Melt on high for 45 seconds, stir well. Then repeat in 20 second batches. You do not want the chocolate to burn it so stir well. It shouldn’t take more than a minute or so.
-Sift together flour, cocoa powder, baking soda, baking powder, and salt.
-Beat eggs, sugars, and vanilla in a large bowl with an electric mixer at medium speed until pale and thick, 3 to 5 minutes. At low speed, mix in melted chocolate until incorporated, then add flour mixture in 3 batches alternately with sour cream, beginning and ending with flour mixture and mixing until each addition is just incorporated.
-Spread batter evenly in pans and tap pans several times on counter to eliminate air bubbles. Bake until cakes pull away from sides of pan and a wooden pick inserted in center of each comes out mostly clean, about 10-20 minutes. You want to check at 10 minutes and then every 3 minutes thereafter. If you use a dark pan check sooner.
-Cool in pans until completely cool, about 1 hour.
Directions for the Filling:
-Combine all ingredients and whip until combined and fluffy. Set aside until you assemble.
Directions for the Frosting:
-Whisk together sugar, flour, cocoa powder, and a pinch of salt in a small heavy saucepan. Over medium heat, whisk in milk and cook, whisking constantly, until mixture boils and is smooth and thick, 3 to 5 minutes.
-Remove from heat and whisk in chocolate and vanilla until smooth.
-Transfer to a plate to cool to room temperature, covering surface with parchment paper to prevent a skin from forming.
-Beat butter with an electric mixer until pale and creamy (approximately 2-4 minutes), then add cooled chocolate mixture a little at a time, beating until frosting is fluffy and spreadable.
To assemble Towers:
-Using a 2½ inch round cutter (or really, a glass can be used) cut shapes into cake, dipping cutter into flower each time. The number of circles you get will depend on the size of the cutter. I got about 35 circles, making 7 little towers.
-Place one circle on plate, top side down, and pipe peanut butter filling in a smooth layer. Continue, finishing with the 4th layer of cake on top.
-Frost outside of cake with a crumb coat, then let harden in fridge for 10-15 minutes.
-Remove cake from fridge and then frost with about half a cup of frosting, smoothing as much as possible.
-Dip an offset spatula in a cup of hot water. Tap off excess water and use it to smooth the frosting.
-To make the decorative border I used a small closed star tip in a piping bag. You could also use the tip in a zipper bag, or forgo the entire thing and eat as is.
-Apply sprinkles liberally (is there any other way?)