For batter, in a large mixing bowl, cream butter and sugar. Beat in egg. Combine 1 cup flour, baking powder and salt; gradually add to creamed mixture alternately with milk. Toss blueberries with remaining flour. (If using frozen blueberries, do not thaw before adding to batter.) Stir blueberries and cream cheese into creamed mixture (batter will be thick). Transfer to a greased 8" square baking dish. For topping, in a small bowl, combine flour and sugar. Cut in butter until crumbly. Sprinkle over batter. Bake at 375°F for 40-45 min. or until a toothpick inserted near the centre comes out clean. Cool on a wire rack.