Melt the butter in a cast-iron skillet over medium heat. Add the sliced peaches, brown sugar substitute, cinnamon, and salt. Let the peaches cook while stirring continuously until slightly softened, about 5 minutes.
Remove from heat, sprinkle xanthan gum over the peaches, and stir until dissolved. Set aside
In a medium mixing bowl, combine all the ingredients for the topping. Use a fork to work everything together until a dough forms.
Separate the dough into 4 or 6 equal balls. Use your hands to pat them into thin discs. Lay the dough discs on top of the peaches in the skillet, overlapping if necessary. Do not worry about completely covering the peaches with the dough.