Blueberry Four Layer Dessert
["1 1/2 c. flour", "1 tsp. baking powder", "2 Tbsp. sugar", "3/4 c. softened margarine", "1/2 c. finely chopped pecans", "2 c. fresh or frozen blueberries", "1/4 c. water", "2 Tbsp. cornstarch", "1/4 c. sugar", "1 (8 oz.) can crushed pineapple, drained", "8 oz. cream cheese, softened", "1 c. powdered sugar", "12 oz. whipped topping, thawed and divided", "1/2 c. chopped pecans"]
["Combine flour, baking powder and 2 tablespoons sugar.", "Cut in margarine to resemble coarse meal.", "Stir in 1/2 cup pecans.", "Press mixture into 13 x 9-inch pan.", "Bake at 350\u00b0 for 15 minutes.", "Cool completely."]
["flour", "baking powder", "sugar", "margarine", "pecans", "blueberries", "water", "cornstarch", "sugar", "pineapple", "cream cheese", "powdered sugar", "whipped topping", "pecans"]