Preheat the oven to 350°F (180°C). Line a 12-cup muffin tin with paper liners. Or, butter or use baking spray and not liners.
In a medium mixing bowl, whisk together 1 cup pumpkin puree, ⅓ cup butter, 2 large eggs, ¾ cup maple syrup, ¼ cup whole milk and 2 teaspoons vanilla extract.
In a separate large bowl, sift the dry ingredients (1 ¾ cups all-purpose flour, 1 teaspoon baking powder, ½ teaspoon baking soda, ½ teaspoon salt, 2 teaspoons ground cinnamon, 1 teaspoon ground ginger, ¼ teaspoon ground nutmeg, pinch of ground cloves and pinch of ground allspice OR 3 teaspoons pumpkin pie spice) and stir to combine.
Add the wet ingredients to the flour mixture and mix just until combined. Do not overmix. Divide the batter evenly between the prepared muffin tin.
Bake for about 20 minutes, or until a toothpick or cake tester inserted in the center of one muffin comes out clean.
Cool on a wire rack before serving.
Store at room temperature for 2 days, in the refrigerator for 4-5 days, or in the freezer for a month. Always well wrapped.