Preheat oven to 300 degrees. Line a 9 inch baking pan with foil, and spray with nonstick spray.
Press the graham cracker crumbs into the pan.
Add cottage cheese and cream cheese to a food processor. Process until smooth, about 2 minutes. Add brown sugar, sugar, sour cream, flour, vanilla, egg, and egg whites. Pulse until just blended. Fold in 3/4 cup of chopped peanut butter cups.
Pour over graham cracker crumbs.
Bake for 1 hour or until almost set on top. Turn off the oven, and let cheesecake set in there for 1 hour with the door closed. Remove from the oven and cool.
Cover and chill for about 8 hours in the fridge.
To serve garnish with the remaining peanut butter cups, and chocolate sauce if desired.