Prep: Preheat oven to 350°F. Grease a muffin tin well with cooking spray or line with paper liners.
Make the Streusel: Melt the butter in a medium mixing bowl. Add remaining streusel ingredients and stir until a semi-crumbly mixture forms. It won't be super dry and crumbly - but it shouldn't be super wet. Add 1 extra tablespoon of flour if it's too wet to crumble over the muffins.
3/4 cup salted butter, melted, 1 and 1/2 cups all-purpose flour, spooned & leveled or weighed out, 1/4 cup granulated sugar, 1/4 cup brown sugar, packed, 1 and 1/2 tsp cinnamon, 1/2 tsp nutmeg, 1/4 tsp salt
Make the Muffins: In a large mixing bowl, whisk together the pumpkin, oil, sugars, eggs, and vanilla. Add all the dry ingredients and stir in just until everything is combined and the last streaks of flour disappear. Don't over mix.
One 15 ounce can pumpkin puree, 1 and 1/2 cups vegetable oil, 3/4 cup brown sugar, packed, 1 cup granulated sugar, 4 large eggs, 1 tsp vanilla extract, 3 cups all-purpose flour, spooned & leveled, 1 and 1/4 tsp salt, 2 tsp baking powder, 2 tsp baking soda, 2 tsp cinnamon, 1 and 1/4 tsp ginger, 3/4 tsp nutmeg, 1/8 tsp cardamom , 1/4 tsp ground cloves
Bake the Muffins: Fill the muffin cups with batter, filling them a little over 2/3 full. (An ice cream scoop makes this easy!) Top each with a generous sprinkle of the streusel, and press it gently into the batter so it doesn't fall off as the muffins rise in the oven. Bake for 18-23 minutes, or until toothpick inserted into the middle of a muffin comes out with some moist crumbs clinging to it.
Make the Glaze: Whisk glaze ingredients together in a small bowl until smooth. Adjust the consistency with a splash more milk if it's thicker than you like. Adjust cinnamon to taste.
1 and 1/2 cups powdered sugar, 2 tbsp real maple syrup, 2 tbsp milk, cinnamon, to taste
Serve + Store: Let the muffins cool in the pan for a few minutes, then gently remove them (I find that using a butter knife to get under them and gently push them up and out works well). Drizzle with the glaze and enjoy while warm! Store leftover muffins in an airtight container at room temp for 2-4 days.