Ingredients

• 1 Water Roux (3 Tablespoons Gluten Free Flour, ½ Cup of Water at Room Temperature)
• 3 Cups Gluten Flour, Plus More for Sprinkling
• ¼ Teaspoon Cream of Tartar
• ¼ Cup Stevia
• 2 Teaspoon Yeast
• 2 Teaspoons Kosher Salt
• 2 Tablespoons Unsalted Butter at Room Temperature
• ½ Cup Plain Yoghurt at Room Temperature
• 1 Cup Dry Non-Fat Milk

Directions

1. To make the water roux, whisk together the flour and water in a small saucepan. Cook over medium-high heat, whisking constantly, until thickened. It is ready when the whisk leaves a visible trail as it moves through the roux. Remove from the heat and allow to cool until no longer hot to the touch.
2. To make the dough, place the flour, cream of tartar, sugar, and yeast in the bowl your bread machine or stand mixer and use a handheld whisk to combine well. Add the salt, and whisk to combine. Add the butter, yogurt, milk and water roux, then attach the dough hook to the stand mixer, and mix on low speed until combined or place the machine on dough setting to completely mix. Raise the mixer speed to medium and mix for about 5 minutes. Continue mixing on dough setting for 5 minutes. The dough will be quite sticky, but should be smooth and stretchy. Spray a silicone spatula lightly with cooking oil spray, and scrape down the sides of the bowl. Transfer the dough to a lightly oiled bowl or proofing bucket large enough for the dough to rise to double its size, and cover with an oiled piece of plastic wrap (or the oiled top of your proofing bucket). Place the dough in the refrigerator for at least 12 hours and up to 5 days.
3. On baking day, Remove the dough from the refrigerator and turn it out onto a lightly floured surface and, using the scrape and fold kneading method and a very light touch, sprinkle the dough with more flour and knead it lightly, sprinkling with flour when necessary to prevent it from sticking, scraping the dough off the floured surface with a floured bench scraper, then folding it over on itself. Repeat scraping and folding until the dough has become smoother. It took 4 times for me.
4. Shaping the buns + the final rise. Place the dough on a pastry sheet, roll out the dough 1/2-inch thick, and the size of your pan. Invert the prepared baking pan on top of the dough to cover it, and quickly turn over the cutting board and baking pan together to invert the dough into the pan. Shake the pan back and forth a bit to distribute it evenly in the pan. Cover the baking pan with lightly oiled plastic wrap, and place in a warm, draft-free location until nearly doubled in size. It took 30 minutes for me. It should nearly reach the top of the baking pan.
5. Baking the buns. About 25 minutes before the buns have finished rising, preheat your oven to 350°F. Once the dough has finished rising, remove the plastic wrap, place the baking sheet in the preheated oven, and bake for about 10 minutes. Turn the heat down to 325°F, remove the buns from the oven, brush the tops with the melted butter, and sprinkle with sesame seeds, if using. Return the baking sheet to the oven and bake until the internal temperature of the buns reaches about 185°F (another 5 to 10 minutes, no more, so the buns stay soft). Allow to cool for about 10 minutes before slicing and serving.