1. Grease a 9-inch springform pan with the softened butter and line the bottom with parchment paper; preheat the oven to 325°F (160°C) and place a large pan of hot water on the lower rack.

2. In a small bowl combine the refrigerated sugar cookie dough with the flour just until the dough feels slightly firmer, then press it evenly into the bottom and a little up the sides of the prepared pan.

3. Bake the cookie crust for 10 to 12 minutes, until the top looks set but not deeply browned, then remove from the oven and let cool slightly while you prepare the filling.

4. Beat the softened cream cheese on medium speed until completely smooth, scraping the bowl as needed, then add the granulated sugar and salt and beat again until light and fluffy.

5. Mix in the sour cream, heavy cream, and vanilla extract on low speed until fully combined and smooth.

6. Add the eggs one at a time on low speed, mixing just until each egg is incorporated so you do not whip in too much air.

7. Gently fold in 1/2 cup of holiday sprinkles with a spatula, reserving some additional sprinkles for decorating the top of the cheesecake.

8. Pour the cheesecake batter over the partially baked cookie crust, smooth the top, and place the pan on the middle oven rack above the pan of hot water.

9. Bake for 50 to 60 minutes, until the edges look set and the center still has a slight wobble when you gently jiggle the pan.

10. Turn off the oven, crack the door open a couple of inches, and let the cheesecake cool inside the oven for 30 minutes.

11. Transfer the cheesecake to a wire rack and cool completely to room temperature, then cover and refrigerate for at least 4 hours or overnight until fully chilled and set.

12. Just before serving, remove the sides of the springform pan, spread the whipped topping or whipped cream over the chilled cheesecake, and finish with extra holiday sprinkles before slicing and serving.