combine butter, 2 tbs. fat free sour cream and lemon or orange liqueur in a food processor and pulse briefly just until blended. Press mixture in bottom of a 9 inch pan and set aside.
Add sweetened condensed milk, lemon juice and 1 cup of sour cream to mixing bowl and beat on low until smooth and creamy. Spread over prepared crust.
spoon cherry pie filling over cream mixture using a small dinner spoon. Bake for 18 minutes or until filling appears to be nicely set. Let cool about 30 minutes. Then Refrigerate until completely cool. Serves 12