Preheat oven to 350°F. Combine flour, brown sugar and oats. Cut in butter until it resembles coarse meal. Press half of the mixture into 8" x 8" pan. Spread partridgeberry jam over crust. Cover with remaining crumbs. Bake for 35 minutes or until golden brown. Let it cool, then cut into squares. Serve with whipped topping or ice cream.