Chocolate Hazelnut Crepe Cake

Name: Chocolate Hazelnut Crepe Cake
Ingredients: 4 large eggs plus 2 large egg yolks; 2 cups/473 milliliters whole milk; 1/2 cup/118 milliliters heavy cream; 1 cup/145 grams all-purpose flour; 1 cup/90 grams hazelnut meal; 1/4 cup/50 grams sugar; 1/2 teaspoon kosher salt; 1 teaspoon pure vanilla extract; 4 tablespoons/57 grams unsalted butter, melted, plus more butter for greasing pan; 6 ounces/170 grams high-quality chocolate, 64 percent cocoa, finely chopped; 1/3 cup/67 grams sugar; 1/3 cup/40 grams cornstarch; 1/4 cup/25 grams good quality cocoa powder; Pinch kosher salt; 2 1/2 cups/591 milliliters whole milk; 6 large egg yolks; 2 tablespoons/29 grams unsalted butter; 3 tablespoons/45 milliliters brandy or strong coffee; 1 cup/236 milliliters heavy cream, whipped to soft peaks; 3 tablespoons/27 grams chopped, toasted hazelnuts; Cocoa powder, for dusting