Chocolate Hazelnut Espresso Cake

Moist marbled chocolate hazelnut cake with a hazelnut milk soak, chocolate hazelnut whipped cream & espresso mascarpone cream.

Add the hazelnuts to a large saute pan and set it over medium heat. Stir the hazelnuts occasionally until start to turn golden brown, then remove them from the heat.
Add half of the hazelnuts (85g) to a food processor, and grind them up until they resemble tiny little crumbles.
Preheat the oven to 350°F / 175°C. Butter a 7" springform pan, then coat the inside with sugar.
To a medium sized mixing bowl, add the flour, hazelnut flour, baking powder, salt, sugar, and cubed butter. Use a hand mixer or a stand mixer fitted with the paddle attachment to beat the mixture together until the butter has completely combined with the dry ingredients and no lumps remain.
Add in the oil, egg, egg white, vanilla, instant espresso, sour cream, and milk. Whisk the ingredients together just until a cohesive batter has formed.
In another small mixing bowl, whisk together the cocoa powder and hot espresso. Add 240g (1 c.) of the cake batter into the chocolate mixture and gently fold the two mixtures together until you have one cohesive batter.
Alternate adding in the espresso hazelnut cake and chocolate cake batter into your prepared pan. Use a knife to gently swirl the batters together. Bake for 40-50 minutes, until a toothpick inserted in the center of the cake comes out with only a few moist crumbs.
While the cake is baking, work on the fillings.

Add the chocolate hazelnut spread, salt, and heavy whipping cream to a medium sized mixing bowl. Beat with a hand mixer or with a stand mixer fitted with the whisk attachment for 3 minutes, until well combined. Add in the instant pudding and beat for an additional 2 minutes.
Cover the mixture and set it aside in the fridge until you're ready to assemble the cake.

Add the mascarpone, sugar, instant espresso, salt, and vanilla to a medium sized mixing bowl. Use a hand mixer (or a stand mixer fitted with the whisk attachment) to beat the mixture just until combined.
While mixing, slowly pour in the heavy whipping cream. Continue mixing until the mixture reaches soft peaks.
Cover the cream and place it in the fridge until you're ready to assemble the cake.

In a small glass, whisk together the hazelnut milk and brown sugar. Set aside in the fridge until you're ready to assemble the cake.

Once the cake has completely cooled to room temperature, slice it in half horizontally twice to get three even pieces. Transfer the espresso mascarpone cream to a piping bag fitted with a large round tip.
Place the bottom piece of the cake back into your springform pan. Brush ⅓ of the hazelnut milk over the cake, then pipe a ring of the mascarpone cream around the edge of the cake. Spread ½ of the chocolate hazelnut cream in the center, then top it with ⅓ of your remaining toasted hazelnuts.
Place the middle layer of cake on top, and repeat.
Brush the remaining pistachio milk over the bottom of the top layer of cake, then place the top layer of cake on to the cake. Cover the cake and place it in the fridge for 30 minutes to firm up.
Once you're ready to serve the cake top it with the remaining espresso mascarpone cream and toasted hazelnuts. Slice, serve, and enjoy!