In the bowl of your stand mixer, combine the warm water (110°F/43°C) with the honey and stir until dissolved. Sprinkle the instant yeast evenly over the surface and let sit for 5-10 minutes until foamy.
In a separate large bowl, whisk together the bread flour, dark rye flour, fine sea salt, and caraway seeds until evenly distributed.
Add the melted butter and molasses to the foamy yeast mixture and stir briefly. Pour in the flour mixture and mix on low speed with a dough hook, or stir by hand, until a rough, shaggy dough forms with no dry flour remaining.
Increase mixer speed to medium and knead for 8-10 minutes, or knead by hand on a lightly floured surface. The dough will remain sticky but should become smoother and more elastic. Avoid adding extra flour; wet your hands with water if needed.
Lightly grease a large bowl with oil or butter. Shape the dough into a ball, place it in the bowl, and turn to coat. Cover with plastic wrap or a towel and let rise in a warm spot for 1 to 1½ hours, or until doubled in size.
Lightly flour your work surface and turn out the risen dough. Gently press down to release some air. Fold into a rectangle, roll tightly from one short end to the other, pinch the seam closed, and tuck the ends under. Place seam side down into a lightly greased 9x5 inch loaf pan dusted with cornmeal if using.
Cover the loaf pan loosely and let rise in a warm spot for 45 minutes to 1 hour, until the dough rises about an inch above the rim. Preheat oven to 375°F (190°C) about 20 minutes before the rise is finished.
Gently brush the top of the risen loaf with beaten egg, sprinkle with extra caraway seeds, and make 1-2 shallow diagonal slashes across the top. Bake for 30-35 minutes until deep golden brown. The internal temperature should register 195-200°F (90-93°C).
Remove the pan from the oven and let cool on a rack for 10 minutes. Run a knife around the edges, turn the loaf out onto the rack, and cool completely for at least 1 hour before slicing with a serrated bread knife.