1 (6 oz.) pkg. lemon Jello
1 (6 oz.) pkg. blackberry Jello
2 c. boiling water
1 c. cold water
2 tbsp. lemon juice
1 (21 oz.) can blueberry pie filling
2 c. sour cream
1/2 c. powdered sugar

Dissolve Jello in hot water, then add cold water, lemon juice and pie filling. Put in 9"x13" dish and chill until firm. Before serving mix sour cream and powdered sugar and spread on top.