In a bowl, cream the shortening and sugar. Beat in egg; mix well. Combine the flour, baking powder and salt; add alternately to creamed mixture with milk. Fold in blueberries. Pour into a greased 9-in. square baking dish.
For topping, combine the sugar, flour and cinnamon; cut in butter until mixture resembles coarse crumbs. Sprinkle over batter. Bake at 350° for 40-45 minutes or until a toothpick inserted in the center comes out clean. Cool for 10 minutes before cutting. Serve warm or cooled.