Description
Layers of buttery chocolate chip cake are stacked with tangy passionfruit and creamy coffee buttercream.
Ingredients
Units
Scale
For the chocolate crumbles:
- 2/3 cup all purpose flour
- 1 tsp cornstarch
- 2/3 cup cocoa powder
- 1/2 cup granulated sugar
- 1 tsp salt
- 6 TB unsalted butter (melted)
For the chocolate chip cake:
- 1/2 cup buttermilk
- 1/2 cup grapeseed oil
- 1 TB vanilla extract
- 1 1/2 cups cake flour
- 1 tsp baking powder
- 1 tsp salt
- 1/2 cup unsalted butter (room temperature)
- 1 1/4 cups granulated sugar
- 1/4 cup light brown sugar (tightly packed)
- 3 eggs (room temperature)
- 3/4 cup mini chocolate chips
For the coffee buttercream:
- 1 cup unsalted butter, soft room temperature
- 4 cups powdered sugar
- 1 TB espresso powder
- 1 TB hot water (as hot as the tap)
- 2 TB heavy cream
To assemble & serve
- 1 recipe passionfruit curd
- 1/2 cup passionfruit puree
- additional chocolate crumbles for garnish, if desired
Instructions
- Make the chocolate crumbles. Preheat the oven to 350F/176C and prepare a baking sheet by lining it with parchment paper. Sift the flour, cornstarch and cocoa powder together into the bowl of a stand mixer, and add the sugar and salt. Mix on low speed with the paddle attachment until combined.
- Add the melted butter and continue to mix until it looks like coarse, wet sand. Spread the crumbs on the prepared baking sheet and bake for 20 minutes, using a dough scraper or butter knife to break them up and stir about every 5 minutes. Remove from the oven and allow the crumbs to cool completely before using in the recipe or storing in a sealed container.
- Make the chocolate chip cake. Preheat the oven to 350F/176C and line a quarter sheet pan with parchment paper, allowing 2-3 inches (5-7cm) to hang over the sides.
- In a small bowl, whisk the buttermilk, grapeseed oil and vanilla extract until completely combined and smooth. In a separate, larger bowl, sift the cake flour and baking powder together and whisk in the salt. Set both bowls aside.
- Combine the butter, sugar, and brown sugar in the bowl of a stand mixer, and beat on medium-high speed with the paddle attachment for 2 minutes. Scrape down the sides of the bowl and beat for another minute. Add the eggs, one at a time, scraping the bowl after each one. Mix on medium-high again for another 2 minutes after the last egg is added, and scrape down the bowl one more time.
- With the mixer on low speed, stream in the buttermilk/oil/vanilla mixture and continue to beat for 4 to 6 minutes. The batter will be very pale, doubled in size and completely smooth. Be patient! You’re basically forcing too much liquid into an already fatty mixture that doesn’t want to make room for the liquid. Stop the mixer, scrape down the bowl, and add the flour mixture all at once. Mix on low speed for just until all the dry ingredients have been incorporated, less than a minute. Don’t overmix! Scrape down the sides of the bowl — if you see any lumps of flour while you’re scraping, gently fold them in.
- Pour the cake batter into the parchment lined quarter sheet pan, spread into an even layer. Tap the bottom of the pan on the countertop to flatten the batter, and sprinkle the mini chocolate chips on top. Be sure to get them to the edges and corners.
- Bake the cake on the center rack in the middle of the oven for 30 to 35 minutes. After 30 minutes, gently poke the edge of the cake with your finger. The cake should bounce back slightly and the center should no longer jiggle. You can also use a cake tester to check the center of the cake for moist crumbs. Leave the cake in the oven for extra time (2-3 minutes) if it doesn’t pass these tests.
- Allow the cake to cool to room temperature before wrapping and refrigerating overnight. The cooled and wrapped cake can be stored in the fridge for up to 5 days.
- To make the coffee buttercream, combine the espresso powder and hot water in a small bowl and stir until dissolved. Set aside and add the cup of butter to the bowl of a stand mixer, using the paddle attachment to beat on medium high speed for 5 minutes. After each minute, stop and scrape the sides of the bowl. After 5 minutes, scrape down the bowl one more time and add half (2 cups) of the powdered sugar. Beat on medium high for 3 minutes and scrape down the bowl. Add the remaining powdered sugar and beat for 3 more minutes. Stir the heavy cream into the espresso powder/hot water mixture and stream into the buttercream while the mixer is still on high speed. Beat for another 3 minutes, until fully incorporated and fluffy. Set aside.
- Prepare the round cake layers. Discard the parchment paper that the chocolate chip cake baked in, and use the cake ring to cut out two full circles and two partial circles from the cake. The two full rounds will be the middle and top cake layers. The two partial rounds and all remaining cake scraps will form the bottom layer of the cake.
- Assemble the cake. Lined a baking sheet or quarter sheet pan with clean parchment paper and set the cake ring in the center. Cut a 20 inch strip of acetate and form it as tightly as possible to the inside of the cake ring. Use a small piece of tape to secure the acetate strip on the outside seam (where the end of the strip overlaps/ends).
- Place the two partial cake layers inside the cake ring, pressing the round edges firmly against the inside of the ring. There should be a gap in the middle. Using the biggest pieces first, firmly pack down as many cake scraps as will fit into that empty space. You should not be able to see the parchment paper anymore, and the packed cake scraps should be even with the partial rounds.
- You’re going to have extra scraps that can’t fit into the empty space between the partial rounds. Scatter them evenly on top of the layer, using the back of your hand to firmly compact the scraps down and really compress them. Although it might seem like you can’t fit anymore, keep going until you’ve used ALL of those scraps.
- Use a pastry brush to soak the cake in 1/3 of the passion fruit puree (not the curd), making sure to get the edges. Spread half of the passion fruit curd in an even layer over the cake and sprinkle a third of the chocolate crumbs evenly over the curd, gently pressing the crumbs in place. Spread one cup of the coffee buttercream as evenly as possible over the chocolate crumbs. It will be tough to get the frosting evenly applied without misplacing the crumbs, but do your best.
- Repeat the puree bath, curd, crumbles and buttercream for the middle layer, using one of the full cake layers this time.
- With 2 layers complete, add the final layer to the top of the cake, bathe with passion fruit puree, and spread with the remaining coffee frosting. Top with the remaining chocolate crumbles.
- Allow to freeze and set for at least 12 hours. This is CRUCIAL! Do not skimp on the freezer time.
- Serve. A couple hours before you are ready to serve the cake, remove it from the freezer and gently pop it out of the cake ring. Transfer the cake to a platter or cake stand and gently peel off the acetate. Let it defrost in the fridge for 2 hours or 1 hour at room temperature. Leftovers can be refrigerated for up to a week or frozen indefinitely.
Nutrition
- Serving Size: 1 slice
- Calories: 572
- Sugar: 45.3 g
- Sodium: 441.9 mg
- Fat: 33.5 g
- Saturated Fat: 16.7 g
- Trans Fat: 0 g
- Carbohydrates: 65 g
- Fiber: 1.2 g
- Protein: 5.6 g
- Cholesterol: 123.9 mg