Chocolate Hazelnut Tart

To prepare crust: Lightly coat a 9-inch removable-bottom tart pan with cooking spray. Line the bottom with parchment paper. Coat the paper with cooking spray.

Pulse hazelnuts in a food processor until finely ground. Add flour, granulated sugar and salt and pulse for a few seconds to combine. Mix egg and melted butter in a small bowl and then add to the food processor. Pulse until combined and a smooth dough forms. Transfer the dough to the prepared pan. Using floured fingertips, press it firmly over the bottom and up the sides. Prick a few times with a fork. Freeze the crust for 15 minutes.

Preheat oven to 375°F.

Place the tart pan on a baking sheet. Line the crust with parchment paper or foil with a 1-inch overhang. Fill with pie weights (or dried beans). Bake until the edges start to turn slightly golden brown, about 15 minutes. Lift out the paper (or foil) and pie weights. Bake the crust for 5 minutes more. Transfer to a wire rack.

Reduce oven temperature to 325°.

To prepare filling: Set a metal bowl over a saucepan of barely simmering water; the bowl should not touch the water. Add chocolate, butter and cream to the bowl and stir with a silicone spatula until smooth. Remove the bowl and set aside to cool slightly.

Combine eggs, brown sugar and hazelnut (or vanilla) extract in the bowl of a stand mixer. Beat with the whisk attachment on medium-low speed until the mixture turns pale yellow and the eggs have tripled in volume, about 5 minutes.

Carefully drizzle and fold the warm chocolate mixture into the eggs with the spatula using a circular motion. The mixture will deflate slightly, but be careful not to lose all the air. Pour the filling into the crust and smooth the surface.

Bake the tart until a toothpick inserted in the center comes out clean, about 30 minutes. Let cool on a wire rack for 30 minutes. Release the pan sides and transfer the tart to a serving plate. Decorate with hazelnut spikes, if desired.