Add the dry ingredients to a bowl or the bowl of your stand mixer: 3 cups oat flour, 3 Tbsp sugar, 1¼ tsp xanthan gum, 1¼ tsp salt. (If using instant yeast, add it with the dry ingredients).
Drizzle in the milk, blending all the time. Add in the 4 Tbsp butter and mix until blended.
Add each egg one at a time, beating each one thoroughly before adding the next. After all three have been added and blended you should have a sticky, smooth, batter.
Cover with a damp paper towel and allow to rise for 1 hour.
Line a large loaf pan (8½" x 4½") with parchment paper and spray or grease. Add the dough to the pan and cover loosely with greased plastic wrap. Allow to rise again 45-60 minutes.
Bake at 350° for 38-42 minutes or until golden brown. Slice and serve warm! Store in an airtight container, and toast to reheat for best texture.