1. In a small bowl, combine the warm water, yeast, and 1/2 tsp sugar; set aside until bubbly.

2. Prepare a small (8.5 x 4.5 x 3″) loaf pan with cooking spray (or grease very thoroughly with butter or oil).

3. In the bowl of a stand mixer, combine the millet and sorghum flours, tapioca starch, salt, baking powder, xantham gum, and 2 TB sugar. Stir gently to combine. 

4. Add the water/yeast mixture, eggs, oil, and vinegar on low speed until combined, then increase the speed to medium and continue to beat another 2-3 minutes, until the dough is smooth and the consistency of thick cake batter. If it’s too thick to pour (think muffin batter), beat in a little more water. 

5. Scrape the dough into the prepared pan (it should be about halfway full) and gently smooth the top. Cover the pan with plastic wrap (tip: spray the wrap with cooking spray to avoid sticking) and leave in a warm place to rise. The proofing should take 45-60 minutes depending on the warmth of the environment and the activity of the yeast, but watch it carefully and do not let the dough rise more than a quarter-inch or so above the top of the pan. 

6. While the bread is proofing, preheat oven to 375 degrees. When the loaf has risen to the desired height, gently brush on the egg wash (if using), taking care not to deflate the nice airy bubbles that have been created. 

7. Place the bread on the middle rack of the oven and bake at 375 degrees for 10 minutes, then reduce the temperature to 350 degrees and bake an additional 55-65 minutes (or even a bit longer), until an instant read thermometer inserted into the center of the loaf reads 195-200 degrees. 

8. Cool the loaf in the pan 5-10 minutes, then remove and cool fully on a baking rack. Wait until the bread is fully cooled before slicing. 

The bread is best eaten within two days. Leftovers can be frozen in individual slices; wrap each in plastic and store in a freezer-safe bag.