Chocolate Hazelnut Torte from Tiffany at the Dessertivore

This show-stopping creation made with Grain4Grain's Barely Barley Spent Grain Flour from Tiffany at The Dessertivore is perfect for family gatherings.  Makes 20-24 servings. 

INGREDIENTS 

For the Torte:

• 1 1/2 cups Grain4Grain Barely Barley Spent Grain Flour (180 g)
• 1/2 cup ground hazelnuts (75 g) (or substitute additional 1/2 cup spent grain flour)
• 1 tablespoon, 1 teaspoon baking powder
• 1/2 teaspoon salt
• 8 large egg whites
• 1/4 cup sugar (50 g)
• 8 large egg yolks
• 3/4 cup sugar (150 g)
• 1 tablespoon hazelnut liqueur or 2 tsp vanilla extract
• 2 tablespoons milk 

For the Chocolate Hazelnut Ermine Frosting:

• 1 1/2 cups milk (355 ml)
• 1 cup sugar (200 g)
• 5 tablespoons cocoa powder (37 g)
• 3 tablespoons water
• 3 tablespoons cornstarch (28 g)
• 1 1/2 cup butter, softened (340 g)
• 1 cup chocolate hazelnut spread (295 g) 

For Assembly:

• 1 1/2 cups heavy cream (355 ml)
• 1 cup chopped hazelnuts (150 g) (optional) 

INSTRUCTIONS 

Make the Torte:

• Preheat the oven to 350° F (180° C) and spray two 9-inch cake pans with nonstick spray. In a medium bowl, combine the spent grain flour, ground hazelnuts, baking powder, and salt. Stir until fully combined.
• In a large bowl, with an electric mixer fitted with a whisk attachment, beat the egg whites on high speed until soft peaks form. Continue to mix, adding the 1/4 cup sugar a little at a time, until the egg whites form stiff peaks. Store whipped egg whites in the refrigerator until ready to add.
• In a large bowl, with an electric mixer fitted with a whisk attachment, beat the egg yolks and the 3/4 cup sugar on high until the mixture is pale yellow and has a pudding-like consistency, about 1-3 minutes. On low speed, mix in the hazelnut liqueur or vanilla extract and the milk.
• Switch to a baking spatula and sprinkle half the flour mixture over the batter, stirring with the spatula until just combined. Repeat with the second half of the flour. Add 1/3 of the whipped egg whites, folding them into the batter with the spatula until just combined. Repeat with the remaining egg whites, folding until there are no more white streaks, but being careful not to overmix.
• Pour the batter into the prepared cake pans and bake at 350° F (180° C) for about 22-25 minutes, or until the cakes are lightly browned on top and spring back a little to the touch. Allow the cakes to cool for at least 45 minutes before assembly. 

Make the Frosting:

• In a 2-qt saucepan, whisk together the milk, sugar, and cocoa powder. In a separate cup, stir together the water and cornstarch until well combined. Set this aside and cook the milk mixture over low heat until the sugar dissolves and it begins to boil. Add the cornstarch mixture and whisk thoroughly. Continue to cook, whisking continuously, until the mixture thickens into a pudding. Remove from the heat and allow it to cool for at least 45 minutes.
• In a large bowl, use an electric mixer to beat the softened butter until it is slightly fluffy, with no lumps. Add the chocolate hazelnut spread and mix again until it is fully incorporated. Next, add about 1/3 of the cooled chocolate pudding and mix on medium speed until the frosting begins to look like a fluffy pudding. Repeat twice more with the remaining pudding, scraping the sides of the bowl so the frosting is mixed thoroughly. 

Assemble:

• Add the heavy cream to a large bowl and use an electric mixer fitted with a whisk attachment. Whip the cream on high speed until it becomes fluffy. Set aside and chop the hazelnuts.
• Cut each of your cakes into 2 layers using a long, thin knife and rotating the cake as you go. You will end up with a total of 4 layers. Place a cake layer on your serving plate, then cover it with 1/4 of the chocolate frosting. Use a spatula to spread the frosting out to the edges of the cake. Sprinkle some of the chopped hazelnuts over the frosting, then top with 1/3 of the whipped cream. Repeat these steps, layering the remaining cakes, frosting, hazelnuts, and whipped cream. Top the final cake layer with chocolate frosting and hazelnuts only.
• This cake should be stored in the refrigerator for up to 3-4 days. 

RECIPE NOTES 

• Whip the egg whites prior to mixing up the cake batter. You can store them in the refrigerator until you’re ready to use them. 
• The egg yolks and sugar for this cake are beaten much longer than usual. As you continue beating on high speed for between 1-3 minutes, the mixture will turn pale yellow, increase in volume, and thicken to the consistency of a thin pudding.
• Make sure to switch to a spatula to stir in the flour. This will help keep the egg whites from deflating.
• To fold in the whipped egg whites, use a large rubber spatula. Add 1/3 of the egg whites at first, and use the spatula to gently turn the batter over on top of the egg whites. Repeat this motion, sometimes starting from the middle of the batter, and sometimes starting from the edge of the bowl, scraping it to make sure all of the batter gets mixed in. Repeat with the remaining egg whites. Fold until there are no longer any obvious white streaks, but be careful not to stir too quickly or overmix, because this will deflate the batter.
• When making the pudding, be sure to stir the cornstarch-and-water slurry right before adding it in. The cornstarch has a tendency to settle on the bottom.
• After the pudding begins to boil, whisk constantly so that it won’t burn.
• The pudding should completely cool before you make the frosting, or it will melt the butter. Also make sure that the butter is well-softened, or the frosting may be lumpy. 
• If you don’t have a turntable to use when cutting the cakes in half, place them on an upside-down cake pan or plate. This will make it easier to see where you are cutting without a plate rim getting in the way.