Add the warm milk to a medium bowl and add the yeast and sugar. The yeast will be activated when the foam forms on top of the mix, about 5-7 minutes. Stir in the applesauce and avocado oil.
Combine the dry ingredients in a large bowl, rice flour, gluten-free flour, tapioca starch, arrowroot starch, flaxseeds, xanthan gum, baking powder, and salt.
Add the yeast mixture with the dry ingredients; the dough will be sticky, don't be alarmed.
Cover the bowl and place in a warm, dry place for about 12 -18 hours.
Remove the dough and place on a lightly greased parchment paper, form into a dough ball.
Cover the dough with a clean, dry kitchen towel and allow it to rise for 60 minutes.
Meanwhile, preheat the oven to 450 degrees F; place a 6 or 7-quart Dutch oven pot in the oven to heat up.
Carefully lift the parchment paper with the dough into the preheated Dutch pot. Cover pot and bake for 45 minutes
Remove the lid and finish baking the bread until golden brown, another 15 minutes.
Transfer bread to a cooling rack. Allow it cool to room temperature (at least an hour, but ideally 2 hours) before slicing and serving.