1) Preheat the oven to 375°F. Grease a 12-cup muffin pan, or line the pan with papers. Spray the papers with non-stick pan spray, to aid release. Note: The streusel topping on these muffins can burn if your oven temperature is too high. If your oven tends to "run hot," bake the muffins at 350°F instead of 375°F.
2) To make the batter: Place the sugar, soft butter, salt, baking powder, nutmeg and vanilla in a mixing bowl, and beat with an electric mixer until fluffy.
3) Beat in the eggs one at a time, scraping the bottom and sides of the bowl between additions.
4) Whisk together the flour or flour blend and xanthan gum. Add to the mixture in the bowl, alternately with the milk.
5) Stir in the blueberries, chopped apple, or fruit of your choice.
6) Scoop the batter into the prepared pan, mounding the cups full. A heaped muffin scoop works well here. Note: the batter will be VERY sticky; that's what it's supposed to be.
7) To make the topping: Combine all of the ingredients to form small crumbs. Sprinkle about 1 tablespoon topping onto each muffin, pressing it in gently.
8) Let the muffins rest for 10 minutes. Then bake them for 20 to 25 minutes, till lightly browned. Remove from the oven, and let sit for 5 minutes before removing from the pan. Best served warm.
Yield: 12 muffins.
*Make your own blend
Many of our gluten-free recipes use our King Arthur Gluten-Free Multi-Purpose Flour, which includes ingredients that reduce the grittiness sometimes found in gluten-free baked goods. Our flour also increases the shelf life of your treats, keeping them fresh longer.
The following make-at-home blend, featuring stabilized brown rice flour, works pretty well when substituted; and it tastes better than a blend using regular brown rice flour.
Whisk together 6 cups (28 1/2 ounces) King Arthur stabilized brown rice flour; 2 cups (10 3/4 ounces) potato starch; and 1 cup (4 ounces) tapioca flour or tapioca starch. Store airtight at room temperature. Note: You can substitute white rice flour for the brown rice flour if you like; it'll make your baked goods grittier (unless you manage to find a finely ground version).