Preheat oven to 425 degrees and spray or line muffin tins. Recipe yields 14-16 muffins.
In a large bowl combine flour, baking soda, baking powder, cinnamon, pumpkin pie spice and salt together and set aside. In a separate bowl whisk together oil, sugar, brown sugar, pumpkin puree, eggs, milk and vanilla extract. Pour into the dry ingredients and stir only until just combined, don't over mix.
Fill muffins tins. I like to fill mine very full.
Crumble Topping: Combine all ingredients and then spoon or sprinkle over muffins batter. Gently press in the topping just slightly to make sure it sticks to the muffins when they rise.
Bake muffins for 5 minutes and then reduce the oven temperature to 350 degrees (don't open the oven door when you do this). This trick helps to give you rounder muffins tops! Bake for an additional 10-15 minutes or until an inserted toothpick or knife comes out clean. Let cool.
Icing is optional! To make icing simply whisk powdered sugar and milk together! Add more milk to make the icing thinner or add more powdered sugar for a thicker glaze. Drizzle on top of cooled muffins and enjoy!