Cook lasagna noodles; drain and cool. Meanwhile, brown the hamburger. Mix together in a bowl the Ricotta cheese, Mozzarella cheese, Parmesan cheese, egg, salt and oregano. Cut lasagna noodles in halves crosswise.
On each half, evenly spread approximately 1/4 cup cheese mixture. Roll up each noodle jelly roll fashion. Mix together the hamburger and spaghetti sauce. Into a greased 9x13 inch baking dish, spoon 1 1/2 to 2 cups hamburger mixture. Arrange rolls on sauce and top with remaining sauce mixture. Bake 45 minutes in a 350 degree oven.
