Step 1Place the oatmeal, cornmeal, brown sugars and salt in a large mixing bowl. Combine the 1/2 cup of milk, molasses, 1/2 cup of water and butter in a saucepan and heat until the butter melts (or combine in a microwave-safe bowl and microwave until the butter melts). Pour the hot liquids over the oatmeal mixture and let stand until cooled.
Step 2Stir the yeast and granulated sugar into the 1/4 cup of warm water and let stand until the yeast is dissolved and foamy. Add to the mixture in the bowl. Add 1 1/2 cups of the all-purpose flour and beat until smooth. Cover and let stand until the mixture is light and spongy, 1 to 1 1/2 hours.
Step 3Beat in the egg, then add the whole-wheat flour. Measure 1 cup of all-purpose flour and add just enough to make a stiff dough that can be kneaded (you will not use all of this flour). Turn the dough out onto a floured board and knead thoroughly, about 10 minutes, working in additional all-purpose flour if the dough is too sticky.
Step 4Clean and grease the mixing bowl. Place the dough in the bowl, turning to grease all sides. Let the dough stand until light and doubled in bulk, about 1 hour. Punch it down, turn it out and knead thoroughly.
Step 5Grease two 8x4-inch loaf pans. Divide the dough in half. Form each half into a loaf and place in the pans. Let the dough rise until doubled in size, 35 to 45 minutes.
Step 6Heat the oven to 350 degrees. Brush the loaves gently with the remaining 2 tablespoons of milk. Bake until the loaves are browned and sound hollow when tapped on top and bottom, 30 to 35 minutes. Turn the loaves out onto a rack to cool.