fudgy chocolate-hazelnut cake

INGREDIENTS

200 g

/ ¾ cup + 2 tablespoons unsalted butter

230 g

/ 8.1 oz. 70 % dark chocolate

large eggs, whites and yolks separated

200 g

/ 1 cup sugar

200 g

/ 7 oz. hazelnuts, roasted and finely ground

3 tbsp

natural cocoa powder (unsweetened)

2 tbsp

cornstarch (or potato starch)

1/4 tsp

salt

2 tsp

instant coffee or espresso dissolved in 1 teaspoon water

1 tsp

vanilla extract

for the ganache:

100 g

/ 3.5 oz. 70 % dark chocolate

60 milliliters

/ ¼ cup heavy cream