To Make The Pumpkin Muffins:

1. Preheat oven to 350 degrees. Prepare 16-18 baking cups with liners, or mist with cooking spray.
2. In a medium bowl, whisk together the dry ingredients (flour, sugar, baking powder, baking soda, cinnamon, ginger, nutmeg and salt) until blended.
3. In a different large bowl, whisk together all remaining ingredients (pumpkin, butter, eggs, vanilla) until well combined. Add this mixture to the dry ingredients, and stir until just combined.
4. Fill the baking cups with the batter until they are each 2/3 full. Top with a tablespoon or so of the crumbled streusel topping. Then bake for 15-20 minutes, or until a toothpick inserted in the middle of a muffin comes out clean. Let cool, then drizzle with the glaze.

To Make The Cinnamon Streusel Topping:

1. Use a fork or your fingers to mix together all of the ingredients until they are evenly combined and crumbly.

To Make The Glaze:

1. Whisk together the butter, powdered sugar and 1 tablespoon of milk until combined and smooth. Add additional tablespoon(s) of milk until the glaze is thin enough to drizzle. You can either drizzle by using a fork and swinging it back and forth over the muffins. Or transfer it to a pastry bag or a ziplock bag with a tiny corner snipped off, and drizzle it that way. OR, you can even just dunk the tops of the muffins straight into the bowl of glaze. Whatever sounds best to you!