1. Preheat oven to 350°F (176°C). Prepare a 9 inch springform pan with a circle of parchment paper in the bottom and grease the sides.
2. To make the cake batter, beat the sugar and butter together until light in color and fluffy, 3-4 minutes. Don’t skimp on the creaming.
3. Add the sour cream and vanilla extract and mix until well incorporated.
4. Add the egg whites and mix until well combined.
5. Combine flour and baking powder in a separate bowl, then add half of the dry ingredients to batter and mix until well incorporated.
6. Add the milk and water and mix until well incorporated.
7. Add the remaining dry ingredients and mix until well incorporated and smooth.
8. Stir in the sprinkles and color the batter, if desired.
9. Spread the cake batter evenly into the bottom of the prepared pan.
10. Bake for 18-20 minutes, or until a toothpick inserted comes out with a few crumbs. Set the cake aside to cool.

TO MAKE THE CHEESECAKE FILLING:

11. Add the cream cheese, sugar and flour to a large mixer bowl and beat on low speed until completely combined and smooth. Be sure to use low speed to reduce the amount of air added to the batter, which can cause cracks. Scrape down the sides of the bowl.
12. Add the sour cream and vanilla extract mix on low speed until well combined.
13. Add the eggs one at a time, mixing slowly to combine after each addition. Scrape down the sides of the bowl as needed to make sure everything is well combined.
14. Stir in the sprinkles.
15. When the cake layer has cooled, reduce the oven temperature to 300°F (148°C). Remove the sides of the springform pan and clean it off, the respray it with non-stick spray. You want to be sure it’s well done so that they cheesecake doesn’t stick to the sides after baking.
16. Reset the springform pan edges around the cake and add the cream cheese filling to the pan.
17. Prepare the pan for a water bath by wrapping the outside of the pan with aluminum foil, then place the springform pan inside another larger pan. Fill the outside pan with enough warm water to go about halfway up the sides of the springform pan. The water should not go above the top edge of the aluminum foil on the springform pan.
18. Bake for 1 hour. The center should be set, but still jiggly.
19. Turn off the oven and leave the door closed for 30 minutes. The cheesecake will continue to cook, but slowly begin to cool as well.
20. Crack the door of the oven for 30 minutes to allow the cheesecake to continue to cool slowly. This process helps prevent cracking.
21. Remove the cheesecake from the oven and water bath wrapping and refrigerate until firm, 5-6 hours or overnight. Once completely cool and firm, remove from the springform pan.

TO FINISH OFF THE CHEESECAKE

22. Add the heavy whipping cream, powdered sugar and vanilla extract to a large mixer bowl and whip on high speed until stiff peaks form.
23. Add the icing color to get the shade of pink you want.
24. Pipe the whipped cream on top of the cheesecake. I used a large round tip, Ateco 808.
25. Add a few more sprinkles on top of the cheesecake, then refrigerate until ready to serve. Cheesecake is best for 3-4 days.