A rich chocolate cake, dreamy chocolate custard, blackberries, and homemade whipped cream—what’s not to love?
For the cake:
- 110g all-purpose flour
- 35g unsweetened cocoa powder
- 1/2t baking soda
- 1/4t baking powder
- pinch of salt
- 62g egg (crack two eggs, whisk together, weigh and discard the excess for snacking later)
- 138g granulated sugar
- 1/2t vanilla extract
- 94g mayonnaise
- 115g room temperature water
For the chocolate custard:
- 500g granulated sugar
- 120g unsweetened cocoa powder
- 1T light corn syrup
- 2 1/2C warm water
- 60g cornstarch
- 4T (56g) unsalted butter
- 1 1/2t vanilla extract
- 6oz blackberries
For the whipped cream:
- Pint of heavy cream
- 1/2C powdered sugar
- 1/2t vanilla extract
Make the cake:
- Line a quarter sheet pan (9×13) with a silicone mat or parchment paper sprayed with nonstick spray. Preheat the oven to 325F.
- In a large bowl, whisk together the flour, cocoa powder, baking soda, baking powder, and salt. Set aside.
- In the bowl of a stand mixer fitted with a whisk attachment, add the eggs, sugar, and vanilla. Whip together for about 5 minutes, or until the mixture is pale. Scrape down the bowl, and continue whipping on medium-high for another 5 minutes, or until the mixture has thickened.
- Turn the mixer on low and add the mayonnaise. Scrape down the bowl and whip over medium to combine. Turn the mixer off and remove the bowl from the stand.
- Using a rubber spatula, alternate adding the flour mixture and water in two additions. Gently folding in your ingredients to avoid overmixing.
- Pour the batter into the pan and use your spatula to evenly spread the mixture to all four corners. Bake for 12-15 minutes or until a toothpick inserted into the center comes out clean. Let cool completely on a rack before running a knife along the edge and inverting onto a parchment-lined surface. Use a cookie cutter (I use the 3.8″ cutter from this set) and cut out as many circles as possible. Keep all the scraps to fill gaps and top the trifles.) Store, tightly wrapped, in the fridge until you are ready to assemble.
Make the custard:
- In a saucepan, add the sugar, cocoa powder, corn syrup, and 2 cups of water. Stir to combine and heat over medium until boiling.
- In a small bowl, combine the cornstarch with the remaining 1/2 cup of water. Thoroughly whisk together until all of the cornstarch is hydrated and the mixture is free of lumps.
- Once the cocoa mixture is boiling, remove it from the heat and add the cornstarch. Place back on the burner (still on medium) and stirring consistently heat until boiling and thickened, about 5 minutes. Turn off the heat, remove the pan from the stovetop, and add the butter and vanilla. Stir until smooth.
- Let cool before scooping the custard into a shallow bowl and store tightly wrapped (with the saran wrap touching the custard to avoid a film from forming) in the fridge until completely cool. This can also absolutely be made the day before to save on time.
Make the whipped cream and assemble:
- Make sure your heavy whipping cream is as cold as possible before starting. In the bowl of a stand mixer fitted with a whisk attachment, add the heavy whipping cream, powdered sugar, and vanilla. Start on a low speed and gradually work your way higher until you get to a med-high/high. Keep whipping until thickened and medium-stiff peaks are formed.
- Chop your blackberries into quarters. Now it’s time to assemble!
- In a highball glass, add a layer of cake (if it doesn’t fill the entire bottom, use scraps to plug any holes.) Spoon in an even spread of custard and top with a layer of blackberries. Add the whipped cream. Repeat the process until you’ve reached the top. I like to top the whole thing with cake crumbs and more blackberries.