This cheesecake is so rich and creamy - I would recommend dividing it into 12 portions.
1 1/2 Tbsp melted butter. 3 oz/2/3 cup chocolate wafer cookie crumbs 1 lb/ 1 3/4 cups carton small-curd low-fat cottage cheese 8 oz package cream cheese 2 large eggs 2 large egg whites, whisked 1 cup sugar 3/4 cup cocoa 1/4 cup orange-flavour liqueur or orange juice 2 tsp grated orange peel 1/3 cup chopped semisweet chocolate
Combine crumbs and melted butter. Pat evenly over bottom and about 1/2 inch up side of a removable-rim 9-inch cheesecake or cake pan (at least 1 3/4 in. deep).
Bake in a 350° oven until crust is slightly toasted, 10 to 12 minutes.
Meanwhile, in a blender or food processor, whirl cottage cheese, cream cheese, eggs, and egg whites until very smooth.*
In a large bowl, mix sugar and cocoa. Add cheese mixture, liqueur, and orange peel.
Heat chocolate in a microwave-safe bowl in a microwave oven at full power in 5-second intervals until soft. Stir until smooth, then scrape into cheese mixture. Beat with a mixer until smoothly blended. Pour into hot or cool crust.
Bake in a 180oC/350oF oven until centre barely jiggles when cake is gently shaken, 40 to 45 minutes. Run a thin-bladed knife between cake and pan rim. Cool and then refrigerate cake, uncovered, until cool, at least 2 1/2 hours. Serve, or if making ahead, wrap and chill for up to 2 days.
Remove pan rim and cut cake into small wedges and serve with creme fraiche or sour cream.
*at this stage I recommend mixing in the yolks gently, then folding in the well whisked egg whites with a metal spoon .