In a large bowl, dissolve yeast and a pinch of sugar in warm water. Set aside to rest for about 5 minutes.
Mix butter or margarine and molasses into yeast. Add 1 cup oat bran, 2 cups flour, and salt. Stir, and add flour as needed to make dough stick together. When dough forms a ball, turn out onto a lightly floured surface. Knead for 8 to 10 minutes, adding flour as needed to make a slightly sticky and moist dough. Place in a buttered bowl, and turn to coat the surface. Cover with a damp cloth, and let rise until doubled in bulk, about 1 1/2 to 2 hours.
Punch down, and form into two round or oval loaves. Place on a greased baking sheet, and allow to rise 1 hour, or until loaves have doubled in size. Sprinkle 1 tablespoon oat bran on top of the loaves.
Bake in a preheated 350 degrees F (175 degrees C) oven for 35 to 45 minutes, or until the tops are a nice dark brown and the bottoms of the loaves sound hollow when tapped.
