2 cups sugar 2 tsp. cream of tartar 1-3/4 cups water Zest and 2 Tbsp. juice from 1 lemon 1 pkg. (14.1 oz.) ready-to-use refrigerated pie crust (2 crusts) 36 RITZ Crackers , coarsely broken (about 1-3/4 cups) 2 Tbsp. butter or margarine , cut into small pieces 1/2 tsp. ground cinnamon MIX sugar and cream of tartar in medium saucepan. Gradually stir in water. Bring to boil on high heat; simmer on low heat 5 min. or until mixture is reduced to 1-1/2 cups. Stir in zest and juice; cool 30 min. HEAT oven to 425°F. Roll out 1 crust on lightly floured surface to 11-inch circle; place in 9-inch pie plate. Place cracker crumbs in crust. Pour sugar syrup over crumbs; top with butter and cinnamon. ROLL out remaining crust to 10-inch circle; place over pie. Seal and flute edge. Cut several slits in top crust to permit steam to escape. BAKE 30 to 35 min. or until golden brown. Cool. CHOCOLATE-WALNUT MOCK APPLE PIE Prepare as directed, sprinkling 1/2 cup each chopped