In the bowl of an electric mixer fitted with a dough hook, mix the flours, oats, salt, and yeast to combine. Add the water, honey, and butter and mix on low speed until the mixture forms a ball around the hook. (This can also be done by hand in a large bowl using a wooden spoon).
Raise speed to medium and mix until the dough is smooth and elastic, 5 minutes more. (This can also be done by hand on a clean surface for 10 to 12 minutes).
Transfer the dough to a lightly greased medium bowl and let rise until doubled in size, about 1 1/2 to 2 hours. Preheat the oven to 375° F.
Shape the dough into an oblong shape by pressing it out into a rectangle about 1-inch thick, then folding it over onto itself to expel excess air. Seal the final fold using the heel of your hand, then gently roll into an oblong loaf. Place the dough, seal side down, into a lightly greased 9-inch loaf pan.
Let the dough rise inside the pan until nearly double in size, 1 1/2 to 2 hours. Brush the surface with water and sprinkle with more oats.
Bake the loaf until golden brown and crusty (and until the internal temperature reads about 195° F), 45 minutes to 1 hour. Cool completely before slicing and serving.
I always carry three kinds of hot sauce in my purse. I have a soft spot for making people their favorite dessert, especially if it's pie. My first cookbook, The Fearless Baker, is out on October 24, 2017.