Hazelnut Torte

Preheat oven to 275 degrees F. Coat an 9-inch springform pan with cooking spray. Line the bottom with parchment paper.

Spread hazelnuts on a rimmed baking sheet. Bake until toasted, about 15 minutes. Let cool slightly. Pulse in a food processor until coarsely ground.

Increase oven temperature to 325 degrees F.

Beat egg yolks and sugar in a large bowl until smooth. Add the ground hazelnuts and butter and beat until fully incorporated. Beat egg whites in another large bowl until stiff peaks form. Fold the egg whites into the batter and mix until no white streaks remain. Scrape the batter into the prepared pan.

Bake the torte until a knife inserted in the center comes out clean, about 50 minutes. Let cool on a wire rack for 15 minutes. Run a knife around the edges to loosen the sides, remove the pan sides and let cool completely, about 1 hour more.