Preheat oven to 325°.
To prepare the crust, combine the first 3 ingredients in a bowl; toss with a fork until moist. Press mixture into the bottom of a 9-inch springform pan coated with cooking spray.
To prepare filling, combine cocoa and Kahlua, and stir well with a whisk. Beat cheeses and sour cream at high speed of a mixer until smooth. Add 1 1/4 cups sugar, flour, and vanilla; beat well. Add eggs and egg whites, 1 at a time, beating well after each addition. Stir in cocoa mixture.
Pour mixture into prepared pan; bake at 325° for 1 hour and 5 minutes or until almost set. Cheesecake is done when the center barely moves when pan is touched. Remove from oven; run a knife around outside edge. Cool to room temperature. Cover and chill at least 8 hours. Garnish with coffee beans, if desired.
Very good. As with most cheesecakes, it tastes best if given plenty of time to "marry" and if brought to room temperature before eating. It is difficult to wait, though!