Boil and drain the lasagna noodles. Spread them onto an olive oil coated pan, turning them to get oil on both sides so they don't stick. Cool.
Place ricotta (or cottage) cheese into blender, add egg and salt and pepper, and blend until smooth. Add sour cream if it's too thick. Mix with mozzarella (except for 1 cup or so for the top) and parmesan in a large bowl. Set aside.
Ladle a cup of sauce into the pan.
Add a layer of noodles, usually 4 side by side, in a deep dish foil lasagna pan. Ladle 1/3 of the rest of the sauce onto the noodles. Add a line of cheese mixture to each noodle.
Repeat the last step twice. Then top with the saved mozzarella cheese.