CRUST: Combine graham cracker crumbs, sugar and butter; set aside 1/4 cup for topping. Press remaining crumb mixture on bottom and sides and up to 1 1/2 inches in a 7x11x2-inch pan; set aside. Dissolve lemon jello in small bowl with boiling water; chill until slightly thick. Beat cream cheese, sugar and vanilla until fluffy. Beat in gelatin. Prepare whipped topping according to package directions. Fold into cream cheese mixture. Pour into prepared pan; sprinkle with remaining crumbs. Chill 3 to 4 hours before serving.