►CRUST: Preheat oven to 325°. Lightly spray a 9” springform pan with non-stick cooking spray and line bottom with parchment paper. Combine flour, sugar, cocoa powder, and salt in a mixing bowl. Drizzle in melted butter and mix gently with a spatula until crumbly. Gently press into prepared pan in an even layer, allowing it to come up the sides about one-quarter inch. Chill for 20 minutes. Bake for 20 minutes. Cool completely at room temperature.

►FILLING: Reduce oven to 300°. Beat cream cheese with sugar in mixer with paddle attachment

until light and fluffy, about one minute. Add sour cream, cocoa powder and salt and mix to combine. Add vanilla, and then eggs one at a time, mixing until they are fully incorporated. With mixer on low, drizzle in melted chocolate. Scrape bowl down as needed to ensure mixture is uniform. Wrap bottom of pan in foil and set it on a sheet pan with a rim. Pour filling evenly into crust, and place pan in oven. Pour about an inch of hot water into sheet pan. Bake 1 hour and 40 minutes; cake should be set, yet slightly wobbly. Cool at room temperature in pan before transferring to the refrigerator to chill completely, at least six hours or overnight.

►CARAMEL SAUCE: Combine sugar and enough water to create consistency of wet sand in a small, deep pot. Place over high heat and bring to a boil—using a wet pastry brush to wash sugar crystals off sides of pot—until it takes on a medium honey-colored hue. Watch carefully but do not stir. In another pot, heat cream and butter until butter melts and mixture begins to steam, but do not allow it to boil. Remove from heat. When caramel has darkened, reduce heat to low and slowly add cream and butter mixture. It will bubble and splatter, so use care. Increase heat to medium and add salt. Simmer for three minutes to thicken, stirring often. Let cool.

►TO SERVE: Release latch on springform pan and remove ring. Place cheesecake on a serving platter and top evenly with about ½ cup caramel sauce. Sprinkle with flaky sea salt.