In a large bowl, combine flour, sugar, pumpkin pie spice, baking soda and salt. Combine eggs, pumpkin and oil; stir into dry ingredients just until moistened. Fold in apples. Fill greased or paper-lined muffin cups three-fourths full. For topping, combine sugar, flour and cinnamon. Cut in butter until mixture resembles coarse crumbs; sprinkle 1 teaspoon over each muffin. Bake at 350° for 30-35 minutes or until muffins test done. Cool in pan 10 minutes before removing to a wire rack. Yield: about 1-1/2 dozen.