In a large mixing bowl, mix together the rye flour, yeast, molasses, and water until it forms a really wet, loose mixture, and there are no visible pockets of dry flour. Set aside for 20 minutes, to allow the rye flour to absorb some of the liquid.
Add the all purpose flour, whole wheat flour, salt, and optional seeds to the rye flour mixture and mix the dough in the mixing bowl for a few minutes, until it forms a wet dough, and there are no visible pockets of dry flour.
On a generously floured work surface, knead the dough for another 5 to 10 minutes, until the dough is a smooth ball. Add a sprinkle of about a teaspoon of all purpose flour or rye flour periodically as you knead the dough, if it is still really sticky.
Lightly oil a clean mixing bowl with olive oil. Place the kneaded dough ball into the oiled mixing bowl. Cover it with a clean kitchen towel and let rise until it about doubles in size, after about 1 hour.
On a lightly floured work surface, tip out the dough and shape it into a round or oval shape. Gently spread the top edges of the dough down the sides and underneath, to create tension on the top. All the seams or edges of the dough should be tucked underneath.
Place the dough on a baking sheet lined with parchment paper or a silicone baking mat. Very lightly dust the top with a little flour, just so the towel doesn’t stick to it. Cover the dough again with a towel and allow to proof for another 1 hour in a warm draft-free spot. The dough is done proofing once it’s puffed up in size (it likely won’t double in size, but it’ll be a little larger). Preheat the oven to 400°F. Bake for 30 to 35 minutes, until the loaf has a crispy crust and sounds hollow when tapped on the bottom. Allow the loaf to cool on a cooling rack for at least 30 minutes before slicing. Enjoy!!