For the Brownies:
4 ounces unsweetened chocolate
¾ cup (1½ sticks) unsalted butter
1¾ cups sugar
3 eggs
1 teaspoon vanilla
½ teaspoon salt
1 cup flour

For the Crumb Crust:
1½ cups or 5 ounces (3 cups or 10 ounces to double) finely ground Oreos, or other chocolate cookie
5 tablespoons (10 tablespoons to double) unsalted butter, melted
1/3 cup (2/3 cup to double) granulated sugar
1/8 teaspooon (¼ teaspoon to double) salt

For the Cheesecake:
3 (8-oz) packages of cream cheese, softened
1 cup granulated sugar
4 large eggs
1 teaspoon vanilla

For the Ganache Glaze:
3 oz. bittersweet chocolate, finely chopped
4 tablespoons (½ stick) unsalted butter
¼ cup heavy cream
½ teaspoon vanilla
1 tablespoon powdered sugar