• Preheat your oven to 400°F. Grease a standard 12-cup muffin tin and set it aside.

Make the pizza dough.

• In a large bowl, place the flour blend, xanthan gum, baking powder, and salt, and whisk to combine.
• Add the yogurt and 2 tablespoons of water, and mix until the dough holds together well.
• If necessary for the dough to clump and hold together easily, without feeling stiff to the touch, add another tablespoon of water and mix to combine.
• Divide the dough into two equal portions. Work with one at a time, and cover the other with plastic wrap so it doesn’t dry out.

Shape the pizza dough.

• Sprinkle a flat work surface lightly with gluten free flour, place the first piece of dough on top of it, and sprinkle it again lightly with more flour.
• Using a rolling pin, roll out the dough into a rectangle that’s about 1/4-inch thick. Fold it over on itself at least once then roll it again, to ensure you’re working with a smooth dough.
• Roll out the dough again into a rectangle that’s about 10-inches long x 8-inches wide, sprinkling lightly with extra flour as necessary if it becomes sticky in spots.
• Spread about half of the tomato sauce on top of the rolled-out dough, leaving about 1-inch clean all around the perimeter.
• Sprinkle with half of the pepperoni slices, then half of the shredded Parmigiano-Reggiano cheese, and finally the shredded mozzarella cheese, still leaving that edge clean. Press the fillings down with your palm to help them adhere to the dough.
• Working from one short end, roll the dough tightly into a coil, pinching the ends and seams as you go. With the seam on the bottom and using a sharp knife, slice the roll by cross-section into 6 equal portions.
• Lift each of the pinwheels carefully and place in its own well in the prepared muffin tin, cut side up. Press each of the pinwheels carefully but firmly into its well to help it fill the space.
• Repeat with the second half of the dough, and the remaining filling ingredients.
• Brush the tops and sides of each pinwheel in its well with the egg wash.

Bake the pinwheels.

• Place the muffin tin in the center of the preheated oven and bake until pinwheels are firm and beginning to brown on the top and sides, and the cheese is bubbling (about 22 minutes).
• Remove the pan from the oven and allow the pinwheels to cool slightly before serving warm.
• Leftovers can be cooled to room temperature, then refrigerated for up to 3 days. Refresh in the microwave before serving, or sprinkle lightly with water and refresh in a 350°F toaster oven until the bread is soft and warm, and the cheese is melted.