How To Make Blueberry Cream Dessert. You will need. 1-1/4 cups finely crushed graham crackers, 1/4 cup sugar, 1/3 cup butter or margarine melted, 1/2 cup sugar, 1 envelope unflavored gelatin, 3/4 cup water, 1 cup sour cream, 1 8-ounce blueberry yogurt, 1/2 vanilla, 1/2 cup whipping cream, 1 cup fresh or frozen blueberries. Step 1. In a medium bowl combine crushed graham crackers, the 1/4 cup sugar, and the melted butter or margarine. Reserve 1/4 of the crumb mixture, press remaining crumbs in bottom of a 2-quart square baking dish. Step 2. In a small saucepan stir together the 1/2 cup sugar and the gelatin, stir in the water. Heat and stir until gelatin and sugar dissolve. In a large bowl combine sour cream and yogurt, gradually stir in gelatin mixture. Stir in vanilla. Chill about 45 minutes. Step 3. In a chilled small mixing bowl beat whipping cream with chilled beaters of an electric mixer on medium speed until soft peaks form. Fold whipped cream into yogurt mixture. Stir in the 1 cup blueberries. Spoon into into crust, spreading evenly. Chill about 4 hours or until set. Cut into squares. Sprinkle some of the reserved crumbs on top of each serving. If desired, garnish with blueberries. Enjoy.