Peanut Brittle Coffee Fudge Cake

I have a brother whose birthday is on the fourth of January. Every year, after all the New Year hoopla, we gather around for the first birthday celebration of the year. I tend to pay a little more attention to his cake than the ones that follow because my soul feels a slight breeze of refreshment when the new year rolls around. Plus, this year was his big 3-0 so I had to think of something more unique.
If there is one thing I know about my brother, it is that his two favorite flavors of all time are peanut butter (or peanuts in general) and coffee. In fact coffee, peanuts and my brother are synced so closely together in my brain that every time I go out of town, I usually bring back something that has to do with those two things. Things like Virginia peanuts from the south or a giant espresso peanut butter cup made by the local craft chocolate shop are no brainers when it comes to souvenir gifts for him.
So I made a cake that combines both flavors. It features alternating layers of fudgy chocolate and coffee scented cake which are sandwiched by a light and fluffy peanut butter frosting. The whole thing is then covered by a vanilla – peanut butter Swiss meringue buttercream and topped with homemade honey roasted peanut brittle. When looking at the recipe, you might wonder why I made two different types of frosting. After years of baking, I realized that as much as I love the texture and flavor of boiled frosting, it does not ice as smoothly as Swiss meringue buttercream. So, these days I make two types of frosting for one cake. Is it a pain in the butt? Yes, but the flavor and the presentation are so worth it.

Peanut Brittle Coffee Fudge Cake
Makes one very tall 8” cake

You will need:

2 – 8” buttermilk coffee cake layers, leveled (recipe below)
2 – 8” chocolate cake layers, leveled (recipe below)
1 batch coffee frosting (recipe below)
1 batch coffee and vanilla Swiss meringue buttercream (recipe below)
1 batch honey roasted peanut brittle (recipe below)

Instructions:

1. On a cake board, place a chocolate cake layer and frost the top with coffee frosting.
2. Top the chocolate cake layer with a coffee cake layer and frost the top with coffee frosting.
3. Add another chocolate cake layer and frost the top with coffee frosting.
4. Top the chocolate cake layer with the coffee cake layer.
5. Use the remaining coffee frosting to crumb coat the cake.
6. Place in freezer for 5-10 minutes to set.
7. Fill an icing bag fitted with a very large round tip with the white swiss meringue buttercream.
8. Remove the cake from the freezer.
9. Ice the cake from the top with the white swiss meringue buttercream, moving slowly down.
10. Once the white frosting runs out, add the light brown swiss meringue buttercream to the same bag and continue moving downwards.
11. Once the light brown frosting runs out, add the deep brown swiss meringue buttercream to the same bag and continue frost down the cake until you get to the bottom of the cake. (The cake will look bulky and messy. This is normal.)
12. Using a flat spatula, start going around the cake and smoothing out the sides.
13. As you move around the cake and start removing frosting, an ombre pattern will appear.
14. Frost the entire cake smooth and then top with shards of honey roasted peanut brittle.

For the Buttermilk Coffee Cake:

Ingredients:
2 large eggs, room temperature
2 egg yolks, room temperature
1 c. black coffee, divided
4 tbsp. powdered buttermilk
1 ½ tsp. vanilla extract
2 tsp. coffee emulsion
270 g. cake flour
300 g. sugar
2 ½ tsp. baking powder
¼ tsp. salt
12 tbsp. unsalted butter, room temperature

Instructions:

1. Preheat oven to 350˚ and grease and line the bottom of two 8” cake pans with parchment paper.
2. In the mixing bowl of a standing mixer fitted with the paddle attachment, mix cake flour, sugar, baking powder, and salt until combined.
3. Mix powdered buttermilk to the cup of black coffee and whisk until combined.
4. Add the butter and ¾ c. of the coffee mixture to the flour mixture and mix on low until combined.
5. Scrape the bowl to mix everything evenly.
6. In a small bowl, whisk eggs, egg yolk, the remaining ¼ c. coffee mixture, and vanilla extract.
7. With the mixer on low, add the egg mixture to the flour mixture slowly until combined.
8. Divide batter evenly amongst the two cake pans and bake for 18-20 minutes, rotating the cake pans halfway.
9. Let cake cool in pan for 10 minutes, then turn out of cake pan and move onto wire cooling rack to cool completely.

For the Chocolate Cake:

Ingredients:
1 ¾ c. all-purpose flour
2 c. sugar
¼ c. natural unsweetened cocoa powder
½ c. Dutch-process unsweetened cocoa powder
2 tsp. baking soda
1 tsp. baking powder
1. tsp. kosher salt
½ c. vegetable oil
2 extra-large eggs, room temperature
1 tsp. vanilla extract
1 c. strong, hot coffee

Instructions:

1. Preheat oven to 350˚ and grease and line the bottom of two 8” cake pans with parchment paper.
2. In a stand mixer fitted with the paddle attachment, mix flour, sugar, both cocoa powders, baking soda, baking powder and salt until fully combined.
3. In a separate bowl, whisk vegetable oil, eggs, and vanilla extract until combined.
4. With the mixer speed on low, add the egg mixture to the flour mixture until combined.
5. Turn off the mixer. With a spatula, scrape the sides of the bowl to fully incorporate the two mixtures.
6. Turn the mixer on low and slowly add the hot coffee to the batter. Once added, raise the speed to medium until completely homogenous.
7. Divide batter evenly amongst the two cake pans and bake for 18-20 minutes, rotating the cake pans halfway.
8. Let cake cool in pan for 10 minutes, then turn out of cake pan and move onto wire cooling rack to cool completely.

Coffee Frosting (for the filling)

Ingredients:
1 ½ c. whole milk
⅓ c. flour
¼ tsp. salt
12 oz. (2 ½ sticks) unsalted butter, room temperature
¾ c. sugar
1 – 1½ tbsp. coffee emulsion

Instructions:

1. In a small pot over medium heat, whisk milk, salt and flour until combined.
2. Continuously whisk mixture until thickened to a pudding like consistency.
3. Once thickened, strain through a mesh strainer into a bowl with a spatula to remove lumps.
4. Place a piece of plastic wrap on top of the flour mixture (to prevent skin from forming) and put bowl into the fridge until fully cool.
5. In a mixer bowl fitted with the whisk attachment, mix the sugar and butter on high speed until fluffy and pale about, 5-10 minutes.
6. Add the chilled flour mixture and continue to whip on high speed until the sugar is completely dissolved and the mixture is no longer gritty, about 5-10 minutes.
7. Add 1 tbsp. coffee emulsion and mix until combined.
8. Taste and if you want a stronger flavor, add another ½ tbsp. coffee emulsion.

Coffee and Vanilla Swiss Meringue Buttercream (for the outside)

Ingredients:

1 ¼ c. sugar
5 large egg whites
3 ½ sticks unsalted butter
2 tsp. vanilla extract
2 tsp. coffee emulsion
brown food gel color

Instructions:

1. Simmer an inch of water in a medium pot.
2. In the bowl of a standing mixer, whisk egg whites and sugar together.
3. Place the bowl over the pot of simmering water and whisk the egg white and sugar mixture continuously until the mixture becomes lighter and no longer grainy.
4. Remove the bowl from the pot and transfer the bowl into the mixer fitted with a whisk attachment.
5. Mix on high until mixture becomes white and fluffy, and cool (check for this by seeing if the outside of the bowl is cool to the touch).
6. Add in vanilla extract and butter one stick at a time until a silky smooth frosting forms.
7. Remove a third of the vanilla frosting into a separate bowl.
8. In the original mixing bowl, add 2 tsp. of the coffee emulsion and whip until light brown and homogenous.
9. Remove half of the light brown frosting into a separate bowl.
10. Add a few drops of brown food gel color and whip until the mixture becomes a deep brown.

Honey Roasted Peanut Brittle

¾ c. honey roasted peanuts
1 c. sugar
½ c. water

Instructions:

1. Line a baking sheet with a silicone mat.
2. In a small pot, boil sugar and water together until the mixture turns amber.
3. Once the mixture turns amber, stir in peanuts and quickly transfer mixture onto the silicone mat using a silicone spatula.
4. Spread the brittle with the spatula so that the peanuts are all one layer.
5. Let cool and break into shards.