Preheat oven to 325°F. Combine graham cracker crumbs and sugar in a bowl. Add melted butter and mix until evenly moistened. Press mixture into the bottom and about 1 inch up the sides of a 9-inch springform pan. Bake for 10 minutes, then cool completely.

Beat softened cream cheese with an electric mixer until smooth and creamy. Add sugar and beat until fluffy. Mix in sour cream and flour until combined. Add eggs one at a time, mixing gently after each addition. Fold in vanilla extract and cotton candy pieces until evenly distributed.

Pour filling over the cooled crust and smooth the top. Wrap the springform pan with foil and place it in a roasting pan with hot water reaching about 1 inch up the sides. Bake for 60 to 70 minutes until the edges are set and the center slightly jiggles.

Turn off the oven and open the door 4 to 6 inches. Let the cheesecake cool in the oven for 1 hour. Remove and cool completely at room temperature, then cover and refrigerate for at least 4 hours or overnight.

Beat cold heavy whipping cream and powdered sugar in a chilled bowl until stiff peaks form.

Remove cheesecake from the springform pan. Spread or pipe whipped cream on top and garnish with additional cotton candy pieces before serving.