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 18 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° until a toothpick comes out clean, 30-35 minutes. Cool in pan 10 minutes before removing to a wire rack.