Preheat oven to 350 degrees Fahrenheit. Line a 12-cup muffin pan with baking cups.
Add flour, sugar, baking powder, ground cinnamon, ground nutmeg, and salt to a large mixing bowl. Whisk to combine ingredients.
If adding chopped nuts or seeds, dried cranberries, or chocolate chips or baking chips, then add those to the bowl and toss to coat with flour mixture.
Add pumpkin purée, applesauce, olive oil, honey, vanilla, and eggs to the bowl. Stir to combine ingredients.
Divide pumpkin muffin batter evenly among baking cups, filling the cups until they are about half full.
Bake 17 to 20 minutes, or until a toothpick inserted into the center of the pumpkin muffins comes out clean. Allow the pumpkin muffins to cool, and then decorate them with sanding sugar, if desired.