Preheat & Prep: Preheat your oven to 375°F (190°C). Line a large baking sheet with parchment paper, or grease a dedicated muffin top pan.
Make the Crumble: In a small bowl, mix the chopped pecans, flour, brown sugar, and cinnamon. Cut in the cold cubed butter using a fork or fingertips until coarse crumbs form. Stir in the maple syrup until clustered. Set aside.
Mix Dry Ingredients: In a large bowl, whisk together the flour, brown sugar, granulated sugar, pumpkin pie spice, baking powder, baking soda, and salt.
Mix Wet Ingredients: In a medium bowl, whisk the pumpkin puree, melted butter, milk, egg (or flax egg), and vanilla extract until smooth.
Combine: Fold the wet ingredients into the dry ingredients just until combined. Do not overmix.
Scoop & Top: Scoop generous 1/4-cup mounds of batter onto the prepared baking sheet, spacing them 2 inches apart, or divide into your muffin top pan. Gently press a portion of the crumble onto the top of each mound.
Bake: Bake for 13 to 15 minutes, or until a toothpick inserted into the center comes out clean. Allow them to cool on the pan for 5 minutes before transferring to a wire rack.