1 1/2 cups chocolate graham cracker crumbs
1/4 cup butter, melted
1 tablespoon granulated sugar
3 (8-ounce) packages cream cheese, softened
1 1/2 cups granulated sugar
4 large eggs, lightly beaten
3 tablespoons unsweetened cocoa
1 cup sour cream
1/2 cup whole buttermilk
2 teaspoons vanilla extract
1 teaspoon distilled white vinegar
2 (1-ounce) bottles red food coloring
1 (3-ounce) package cream cheese, softened
1/4 cup butter, softened
2 cups powdered sugar
1 teaspoon vanilla extract
Combine graham cracker crumbs, melted butter, and 1 tablespoon granulated sugar and press mixture into bottom of a 9-inch springform pan. Set aside.
Beat 3 packages cream cheese and 1 1/2 cups granulated sugar at medium-low speed with an electric mixer (1 minute). Add eggs, mixing on low speed just until fully combined. Add unsweetened cocoa, sour cream, buttermilk, vanilla extract, vinegar and red food coloring beating on low speed until fully incorporated. Pour batter into prepared crust.
Bake at 325° for 10 minutes; reduce heat to 300°, and bake for 1 hour and 15 minutes or until center is firm. Run knife along outer edge of cheesecake. Turn oven off. Let cheesecake stand in oven 30 minutes. Remove cheesecake from oven; cool in pan on a wire rack for 30 minutes. Cover with plastic wrap and chill for 8 hours.
To make the topping, beat a package of cream cheese and 1/4 cup butter at medium speed with an electric mixer until smooth; gradually add powdered sugar and vanilla, beating until smooth. Spread evenly over top of chilled cheesecake. Carefully remove sides of springform pan.