PLACE gingersnaps in lightly greased 9-inch square baking pan; sprinkle with raisins.
BEAT eggs, milk and sugar with wire whisk until well blended. Pour evenly over gingersnaps; stir until well blended. Cover with foil. Refrigerate at least 2 hours.
PREHEAT oven to 325°F. Bake dessert 45 minutes or until knife inserted 1 inch from center comes out clean, removing the foil after 30 minutes. Cool slightly before cutting into 9 squares. Serve warm topped with the whipped topping. Store leftover dessert in refrigerator.