Preheat the oven to 375°F. Grease a 12-cup muffin tin or line with paper liners.
In a medium bowl, whisk together the flour, baking powder, baking soda, cinnamon, nutmeg, cloves, ginger, and salt.
In a large bowl, combine the pumpkin puree, brown sugar, eggs, oil, and vanilla extract. Mix until well blended.
Add the dry ingredients to the wet ingredients and mix just until combined. Do not overmix.
Fold in the apples and walnuts.
Divide the batter evenly among the prepared muffin cups. Bake for 20–25 minutes, or until a toothpick inserted into the center of a muffin comes out clean.
Cool the muffins in the pan for 5–10 minutes, then transfer them to a wire rack to cool completely.
Interesting Facts
Pumpkin is a type of winter squash that is native to North America.
Apples are a member of the rose family and are one of the most widely cultivated fruits in the world.
Walnuts contain healthy fats and are packed with vitamins and minerals.