Combine 1/2 cup warm water, 1/4 cup spelt flour, yeast, and white sugar in a very large mixing bowl. Let the yeast proof and grow for about 5 minutes.

Stir in remaining water, oats, brown sugar, vegetable oil, and molasses. Add salt, then add remaining spelt flour, 1 cup at a time, and stir until dough starts to pull away from the sides of the bowl.

Transfer the dough to a generously oiled bowl, turning dough several times to oil all sides so it won't stick or dry out. Let rise in a warm place until doubled in size, about 1 hour. Divide dough into 4 equal pieces and shape into loaves. Transfer loaves to greased loaf pans and let rise until dough is about 1/2 inch higher than the top of the pans, about 1 hour longer.

Preheat the oven to 350 degrees F (175 degrees C).

Bake loaves in the preheated oven until tops are brown, about 30 minutes. Let cool in the pans for 15 minutes, then remove from the pans and finish cooling on wire racks.