In a large mixing bowl, combine the water, oats, maple or brown sugar, honey, butter, salt, and cinnamon. Let cool to lukewarm (100°F to 110°F), which typically takes about 10 to 15 minutes; stir the mixture several times to help things along, if you like., Weigh your flour; or measure it by gently spooning it into a cup, then sweeping off any excess. Add the yeast and flours, stirring to form a rough dough. Knead (about 10 minutes by hand, 5 to 7 minutes by machine) until the dough is smooth and satiny., Transfer the dough to a lightly greased bowl, cover the bowl with lightly greased plastic wrap, and allow the dough to rise for 1 hour. Since the dough is warm to begin with (from the boiling water), it should become quite puffy., Divide the dough in half, and shape each half into a loaf. Place the loaves in two greased 8 1/2" x 4 1/2" bread pans., Cover the pans with lightly greased plastic wrap and allow the loaves to rise until they've crowned about 1" over the rim of the pan, about 1 to 2 hours., Bake the loaves in a preheated 350°F oven for 35 to 40 minutes, tenting them lightly with aluminum foil after 25 minutes, to prevent over-browning. Remove them from the oven when they're golden brown, and the interior registers 190°F on a digital thermometer., Turn the loaves out onto a rack to cool. Store at room temperature, well-wrapped, for several days; freeze for longer storage.