In a small bowl combine the yeast and ½ cup warm water (not boiling!). Stir to combine and set aside for about 5 minutes. This will soften the yeast and bubbles will start to form.
Bring 1 ¼ cups of water to a boil. Once boiling, remove it from the heat and add it to a large bowl. Add 1 cup of rolled oats and molasses to the water. Stir to fully combine.
Cut the butter into cubes and add them to the water/oat mixture. Stir until the butter almost fully melts. Allow the oat mixture to cool down until it reaches about 110°F, about 5 to 10 minutes.
Once the mixture has cooled, add the softened yeast. Stir to fully combine, then add the salt.
Using a wooden spoon, add about ½ cup of flour at a time to the oat mixture. Stir until the flour has been fully incorporated. Repeat this process until you can't easily add more flour in. This should take about 4 cups of the flour.
Transfer the dough to a lightly floured surface and knead in more flour, continuing to add in a small amount at a time. The dough may take the full 5 ½ cups of flour depending on the humidity and how the flour was measured.
Once the dough isn't sticking to the counter, the dough is ready to rise. Grease a large bowl, add the dough to the bowl, and cover it with a tea towel or plastic wrap. Set aside and allow to rise for about 1 ½ to 2 hours or until the dough has doubled in size.
Meanwhile, grease and line 2 bread loaf pans with parchment paper.
Once the dough has doubled in size, turn the dough out onto a lightly floured surface and dived the dough into 2.
Flatten 1 of the dough balls in to a 8"x16" rectangle then roll it up into a loaf shape, tucking the edges in. Roll the loaf in 2 tablespoons of rolled oats that have been sprinkled on the work surface. Place the loaf in one of the prepared loaf pans.
Repeat step 10 for the second dough ball.
Allow the loaves to rise in the pans for 30 minutes before placing them in the oven.
About 10 minutes before the dough has finished rising in the loaf pans, preheat the oven to 375°F.
Bake at 375°F for 50 minutes or until the top and sides are golden brown. You can also check the doneness by gently tapping on the top of the loaf with the handle of a wooden spoon. If it sounds hollow, the bread is done.
Place the loaves on a cooling rack in the loaf pans for 10 minutes. After 10 minutes remove the bread for the loaf pans and allow to cool for another 10 minutes before slicing and serving.