In a large bowl, mix warm water, molasses, and yeast. Let sit for 5–10 minutes until foamy.
Whisk rye flour, bread flour, salt, and caraway seeds in a separate bowl.
Add dry ingredients and oil to the yeast mixture. Stir until a shaggy dough forms.
Turn onto a floured surface and knead for 8–10 minutes until smooth (add flour if sticky).
Place dough in a greased bowl, cover with a towel, and let rise in a warm place for 1–2 hours until doubled.
Punch down dough, shape into a loaf, and place in a greased loaf pan. Cover and rise for 45–60 minutes.
Preheat oven to 375°F (190°C). Bake for 35–40 minutes until the loaf sounds hollow when tapped.
Let cool on a wire rack for at least 30 minutes before slicing.