Preheat oven to 325°. Line a 9-inch springform pan with parchment paper; spray with cooking spray.
In a small bowl, stir together graham cracker crumbs, melted butter, ¼ cup granulated sugar, and ¼ teaspoon salt. Press crumb mixture into bottom and 1 inch up sides of prepared pan.
Bake until dry, about 12 minutes. Remove from oven. Reduce oven temperature to 275°. 4. In a small microwave-safe bowl, combine chocolate and cream. Microwave on high in 20-second intervals, stirring between each, until chocolate is melted and mixture is smooth (about 40 seconds total).
In the bowl of a stand mixer fitted with the paddle attachment, beat cream cheese at medium-high speed until smooth, about 1 minute. Add remaining 1½ cups granulated sugar, beating until smooth, about 1 minute, stopping to scrape sides of bowl as needed. Add eggs, sour cream, cocoa, vanilla, and remaining ¼ teaspoon salt; beat until smooth, about 1 minute. Slowly add chocolate mixture, beating just until combined. Pour into prepared crust.
Bake until top appears dry and center is slightly jiggly, about 2 hours and 15 minutes. Turn oven on, and leave cheesecake in oven with door closed for 20 minutes. Remove from oven, and place on a wire rack. Let cool at room temperature for 20 minutes. Refrigerate until chilled, about 2 hours or overnight. Remove from pan. Garnish with marshmallow crème, marshmallows, and confectioners’ sugar, if desired.
Recipe by Southern Lady Magazine at https://southernladymagazine.com/hot-chocolate-cheesecake-recipe/