Beat cream cheese with egg yolks until smooth. Beat in sugar, flour, sour cream, lemon juice and vanilla.
Whip egg whites until firm peaks appear. Fold gently into cheese mixture.
Pour batter into 8- or 9-inch spring form pan. Bake 1 hour and 10 minutes at 325 degrees. Center will appear a little shaky, but a knife inserted should come out relatively clean.
Top with favorite topping.