01 - Preheat the oven to 350°F. Line a 12-cup muffin tin with paper liners or lightly grease each cup.
02 - In a bowl, combine all-purpose flour, light brown sugar, ground cinnamon, ground nutmeg, and salt. Add the cold, cubed butter and cut in using a fork or your fingers until the mixture forms coarse crumbs. Refrigerate the crumble until use.
03 - In a large mixing bowl, whisk together the flour, baking powder, baking soda, salt, cinnamon, nutmeg, cloves, and ginger until thoroughly combined.
04 - In a separate bowl, whisk the pumpkin purée, light brown sugar, granulated sugar, vegetable oil, eggs, milk, and vanilla extract until smooth and well-incorporated.
05 - Add the wet mixture to the dry ingredients, stirring gently until just combined. Take care not to overmix.
06 - Divide the batter evenly among the prepared muffin cups, filling each about three-quarters full.
07 - Sprinkle a generous amount of spiced crumble over each portion of batter.
08 - Bake for 20 to 22 minutes, or until a toothpick inserted into the center comes out clean.
09 - Allow muffins to cool in the tin for 5 minutes. Remove and transfer to a wire rack to cool completely.
10 - Mix powdered sugar, milk, and vanilla extract in a small bowl until a smooth glaze is formed. Drizzle over the cooled muffins if desired.