1-2/3 cups gluten free flour blend
1-1/3 cups granulated sugar
1 tablespoon gluten-free pumpkin pie spice
¾ teaspoon baking soda
¼ teaspoon salt
1 teaspoon xanthan gum
1-1/3 eggs, slightly beaten (beat 2 eggs in a measuring cup; throw away 1/3 of it)
2/3 cup canned pumpkin puree (not pumpkin pie filling)
1/3 cup vegetable oil
1/3 cup milk
1 large apple, peeled, cored, and chopped ¼ (about 1-1/3 cup)
Preheat to 350F. Insert liners in 12 muffin cups. Combine flour, sugar, and next 4 ingredients in a large bowl. Fluff with a fork until well blended. In a smaller bowl, combine egg, pumpkin, oil, and milk. Add pumpkin mixture to flour mixture and mix with a fork just until uniformly moistened. Fold in apple and divide into muffin cups. Add streusel topping, below.
1 tablespoon plus 1 teaspoon gluten free flour blend
2 tablespoons plus 2 teaspoon granulated sugar
¼ teaspoon ground cinnamon
2 ¾ teaspoon cold butter, cut into pieces
Combine in small bowl or the bowl of a mini food processor. Cut in the butter using two knives in a crossing motion or pulse in mini processor until mixture resembles coarse crumbs. Sprinkle topping evenly over muffin batter.
Bake in preheated oven for 25-30 minutes (test with a toothpick every 2 minutes starting at 23). Cool for 5 minutes in the pan, then turn out.