Blueberry Chocolate Cake Recipe

Preheat the oven to 350F/177C convection and grease and line three 6 inch (15cm) round pans with baking spray and parchment paper.*
In a large bowl, whisk together the flour, sugar, cocoa powder, baking powder and salt until they're well combined.
240 grams all-purpose flour spooned and leveled, 400 grams granulated sugar, 80 grams dutch-process cocoa powder spooned and leveled, 1 Tbsp baking powder, ½ tsp salt
In a separate large bowl, whisk together the oil, eggs, coffee and milk, until they're well combined.
180 mL canola oil or any neutral oil, 2 large eggs room temperature, 180 mL coffee room temperature*, 180 mL milk room temperature
Sift the dry ingredients over the wet ingredients and then whisk together until the batter is completely smooth.
Distribute the batter evenly among the three pans, about 16oz, in each, and bake for 35 minutes. The edges should release from the pans and the top should spring back when you press on it gently.
Flip the cake over onto a tea towel and allow it to cool to room temperature.

In a small pot, over medium heat, combine the blueberries (no need to thaw if they’re frozen) with the sugar and lemon. Stir until the sugar starts to dissolve and then simmer on medium-low heat for 10-15 minutes, until it’s thickened.
280 grams blueberries frozen or fresh (regular or wild blueberries), 50 grams granulated sugar, 1/2 medium lemon
Cool completely and refrigerate before assembling the cake.

Place the dark chocolate in a medium bowl and place the heavy whipping cream into a small saucepan.
150 grams dark chocolate chips, 150 mL heavy whipping cream
Heat the cream over medium heat until it comes to a simmer (bubbling all around the edge).
Pour the cream over the dark chocolate and cover the bowl with a lid or plastic wrap for about 5 minutes, so the chocolate melts.
Use a rubber spatula to gently stir the ganache until they're completely smooth.
Cover again and allow it to cool completely to room temperature. Refrigerate before assembling the cake.

Bring a small pot with 1/2 cup of water to a boil and lower the heat to simmer.
Place the egg whites and granulated sugar in the bowl of a stand mixer and place the bowl over the simmering water for 5-10 minutes, whisking intermittently until the granulated sugar is completely dissolved.
4 large egg whites room temperature, 200 grams granulated sugar
Once the sugar is dissolved, remove the bowl of egg whites from the heat. Use the whisk attachment to beat the egg whites with the sugar. Beat for 7-10 minutes on high speed and then lower the speed to low-medium.
Slowly add 2 Tbsp of butter in at a time. Wait for the butter to incorporate before adding the next chunk. Once all the butter is added, turn the mixer up to high speed for a few seconds, until it comes together.
227 grams unsalted butter room temperature
Then use a rubber spatula to scrape the edge of the bowl. Add the vanilla bean paste (or extract) and salt and beat until it's fully combined.
2 tsp vanilla bean paste, 1/8 tsp fine sea salt
Add the jam to the buttercream mixing just until it's combined and smooth.
1/4-1/2 cup blueberry jam chilled (I did just under 1/4 cup because I didn’t want the color so dark but the buttercream can hold up to 1/2 cup of jam if you want a darker color and flavor).

Pipe a border around the edge of the first layer of cake. Fill it in halfway with a thin layer of blueberry jam and then top it with the chocolate ganache. Make sure they don’t spill over the border.
Place the second layer on top and then repeat with the last layer.
Refrigerate the cake for at least an hour so it’s solid before frosting the outside with the rest of the buttercream.