Ingredients
Brownie
Baking spray
400 g (60% cacao) bittersweet chocolate, coarsely chopped
340 g unsalted butter
80 g unsweetened cocoa
90 ml canola oil
30 ml vanilla extract
470 g granulated sugar
220 g packed light brown sugar
6 large eggs
120 g all-purpose flour
30 g cornstarch
1 1/2 tsp kosher salt
1/2 tsp baking powder
Ganache
200 g (56% cacao) semisweet chocolate, coarsely chopped
180 ml heavy cream
15 g unsalted butter
1/8 tsp kosher salt
60 g rainbow candy-coated chocolate pieces
Directions
Step 1
Gather all the ingredients.
Step 2
Prepare the Brownies: Preheat the oven to 175°C (350°F). Line a 33 x 23 cm (13 x 9 inch) baking pan with aluminum foil, leaving a 5 cm (2-inch) overhang on the short sides. Coat the foil and sides of the pan with baking spray and set aside.
Step 3
In a large microwavable bowl, microwave the bittersweet chocolate and butter on HIGH, stirring in 30-second intervals, until fully melted and smooth, about 2 minutes in total. Whisk in the cocoa, canola oil, and vanilla until fully combined.
Step 4
Whisk the granulated sugar and brown sugar into the chocolate mixture until combined. Add the eggs one at a time, whisking until smooth and combined after each addition, about 2 minutes in total. Gently fold in the flour, cornstarch, salt, and baking powder until just combined, ensuring not to overmix the batter, about 45 seconds.
Step 5
Transfer the batter to the prepared baking pan.
Step 6
Bake in the preheated oven until set and a wooden pick inserted in the center comes out with a few moist crumbs, for 55 to 60 minutes. Remove from the oven and let it rest in the pan on a wire rack until it reaches room temperature, about 1 hour. Once at room temperature, cover and place it in the refrigerator to chill completely, for at least 1 more hour.
Step 7
When the brownie has chilled, prepare the Ganache: Place the semisweet chocolate in a medium mixing bowl and set aside. Bring the heavy cream to a simmer in a small saucepan over medium-high heat, stirring occasionally. Pour the hot cream over the chopped chocolate and whisk until the chocolate is fully melted, about 45 seconds. Whisk in the butter and salt until smooth and shiny and set aside.
Step 8
Invert the cooled brownie onto a large cutting board and discard the aluminum foil. Using a serrated knife, trim and discard the outer edges, about 1/4-inch on all sides. Using an offset spatula, spread the ganache in an even layer over the top of the brownie. Sprinkle the rainbow candy-coated chocolates evenly over the top. Chill the brownie, uncovered, until the ganache is mostly set, about 5 minutes.
Step 9
Cut the brownie into 12 even (10 x 5 cm / 4 x 2 inch) pieces. Using the back of the knife, make an indent going crosswise along the center of each brownie.