Prepare as above through step 5. Cover unbaked lasagna; chill for up to 24 hours. To serve, bake, covered, in a 375 degree F oven for 40 minutes. Uncover; bake about 20 minutes more or until heated through. Let stand for 10 minutes before serving.
For mess-free assembly, spoon the filling into a resealable plastic bag. Snip off one corner of the bag; squeeze the bag to pipe the filling over the noodles in the baking dish.
Substitute 6 no-boil lasagna noodles (one-third of a 9 ounce package) for the regular lasagna noodles and skip step 3. Omit the tomatoes, tomato sauce, and Italian seasoning, fennel seeds, and pepper. For sauce, stir a 26-ounce jar pasta sauce into the browned meat mixture. Do not simmer. Continue as directed in step 4.
Prepare Classic Lasagna as directed, except omit beef or sausage. Add 2 tablespoons olive oil to the skillet; heat over medium-high heat. Add 1 pound fresh cremini mushrooms, quartered, and 1 yellow or red sweet pepper, cut into strips, with the onion and garlic; cook for 5 minutes. Stir in 1 1/2 cups coarsely chopped zucchini and/or yellow summer squash; cook for 3 to 5 minutes more or until vegetables are tender. Continue as directed.