Preheat oven to 350 degrees F.

Spray a 9-inch baking pan with cooking spray and set aside.

Separate two eggs, putting each white in a separate bowl (discard yolks or save for another use); set aside.

In a small mixing bowl, beat butter and 3/4 cup sugar until crumbly. Add the whole egg, one egg white and vanilla, mix well.

Combine flour and cocoa; add to egg mixture and beat until blended.

Pour into prepared pan and set aside.

In a mixing bowl, beat cream cheese and remaining sugar until smooth. Beat in the second egg white. Drop by rounded tablespoonfuls over the batter; cut through batter with a knife to swirl.

Bake at 350° for 25-30 minutes or until set and edges pull away from sides of pan.

Cool on a wire rack.