This Mint Julep Layer Cake is a delicious, moist chocolate bourbon cake with a mint swiss buttercream and chocolate ganache drip. Perfect for Derby Day or anyone that loves mint juleps!
1/2 c. bourbon
1/4 c. packed light brown sugar
2 TB water
2 1/2 c. AP flour
2 tsp baking powder
1/2 tsp baking soda
1/2 tsp salt
2 large eggs
1 egg yolk
1 c. sour cream
2 tsp vanilla extract
12 TB (3/4 c.) unsalted butter
1/4 c. vegetable oil
4 TB instant espresso or ground coffee
1 1/2 c. water
1 c. cocoa powder
1 c. granulated sugar
3/4 c. packed light brown sugar
7 large egg whites
2 c. granulated sugar
2 c. unsalted butter, cubed and softened
1 1/2 tsp mint extract
green food gel
3 oz. dark or semi sweet baking chocolate
1/3 c. heavy cream
In a small saucepan, combine the brown sugar and water. Bring to a boil, then lower the heat to a simmer, stirring occasionally until thickened, about 10 minutes. Stir in the bourbon and set aside to cool.
Preheat the oven to 350°F, then grease and line three 8 inch round cake pans with parchment.
In a large bowl, sift together the flour, baking powder, baking soda and salt. In a separate, smaller bowl, combine the eggs, egg yolk, sour cream and vanilla. Set aside.
Set a large saucepan on medium high heat and melt together the butter, oil, espresso or coffee and water. Stir in the cocoa, sugar and brown sugar until dissolved, then remove from heat.
Add the sour cream mixture to the large saucepan and stir to combine, then whisk in the flour mixture until smooth.
Divide the mixture evenly among the prepared cake pans, then bake for 20 – 25 minutes, or until a toothpick inserted in the center comes out clean.
Let cool completely, at least 20 minutes, before assembling.
In a large bowl or the bowl of a stand mixer, whip the egg whites and sugar together until just combined.
Place the bowl over a large pot of simmering water (double-boiler or bain marie) and whisk constantly 2-3 minutes until the sugar has dissolved and the mixture looks clear.
Return the bowl to the stand mixer and whip on medium-high 5-10 minutes until the mixture is glossy and white, and you have a stiff meringue (when you pull the whisk away from the mixture it should leave a stiff peak).
Switch to the paddle attachment (or beaters if using a hand mixer) and beat on medium speed, slowly add the butter a few cubes at a time and the mint extract.
Dip a toothpick into the green color gel and add to the buttercream, then mix on low speed until no streaks remain. Add more color until you reach the shade of green you desire.
In a small bowl, microwave the chocolate and cream for 30 seconds, stir, then microwave for another 10-20 seconds. Stir slowly, making sure not incorporate too much air, until fully combined and smooth. Let cool slightly and transfer to a condiment bottle (optional).
Slice off the tops of each cake (remove the dome) to achieve even layers and peel off the parchment paper and discard. Place 1 layer of cake on a cake stand or serving dish, brush on 1/3 of the simple syrup, then pipe or spread on the buttercream (amounting to roughly a 1/2″ layer of frosting). Repeat with the remaining layers, then spread buttercream around the entire cake. Use an angled spatula or dough scraper to smooth the edges. Refrigerate for a minimum of 30 minutes.
Pipe on the remaining buttercream and decorate however you’d like. To get results like the photos above, use a #2D tip to pipe on roses, then use condiment squeeze bottle filled with the ganache to drip it down the sides. Spread the rest of the ganache on the top (the narrow tip of the bottle will help get it into hard to reach areas, but use a small angled spatula for the rest)
Store the cake for up to 10 days in the fridge, but let it come to room temperature before serving.
To see some of the cake decorating techniques I mention above, check out the Preppy Kitchen facebook page.