Combine first 4 ingredients in a bowl. Firmly press mixture into bottom and 1 inch up sides of a 9-inch springform pan coated with cooking spray. Set aside.
Combine 1/2 cup sugar, flour, vanilla, and cheeses; beat at medium speed of a mixer until well-blended. Add egg whites and 2 tablespoons milk; beat well. Combine 1/2 cup batter, 1 tablespoon milk, 2 tablespoons sugar, and cocoa; stir well. Spoon remaining batter alternately with cocoa mixture into prepared crust. Swirl together using the tip of a knife. Bake at 425° for 15 minutes. Reduce oven temperature to 250° (do not remove pan from oven); bake 45 minutes or until set. Cool completely on a wire rack. Garnish with chocolate syrup and raspberries, if desired.