In the bowl of your stand mixer, whisk together the first quantity of Whole Wheat Flour with the brown sugar, salt, and yeast.
Using the paddle attachment and turning the mixer onto the lowest speed, mix in the egg, brown butter, molasses, and milk. Turn the speed up to medium and beat for 3 minutes.
Switch to the hook attachment, then with the mixer on speed 2 add the remaining flours a little at a time until it's all incorporated.
Mix on speed 2 for 10 minutes, then turn out onto a floured work surface and shape the dough into a tight ball.
Coat your mixing bowl with oil and place the dough ball inside, cover and let rise in a warm spot until doubled in size (about 1 hour).
Punch down the dough and turn out onto a floured work surface. Cover and rest for 5 minutes, then divide into 4 equal pieces (or 2 equal pieces if you want to make sandwich bread sized loaves!)
Work each piece into a loaf shape, then place in parchment lines loaf pans. Cover and let proof until doubled in size (about another hour).
Bake at 350° for about 35 minutes, or until the bread temps to 200°F.
Once finished, remove the loaves from the pans and set on a rack to cool completely before cutting. Cut into slices as desired and enjoy!