Step 1

Cook lasagna noodles in a pot of boiling salted water, until slightly undercooked, or according to package instructions, undercooking by 2 minutes. Drain, toss with oil and set aside.

Step 2

Spread 1 cup (250 mL) of the tomato sauce over bottom of prepared slow cooker stoneware. Cover with 3 noodles. Spread with one-third each of the ricotta, sweet potatoes and dried Italian seasoning and one-quarter of the tomato sauce and mozzarella. Repeat twice. Cover with final layer of noodles. Pour remaining sauce over top. Sprinkle with remaining mozzarella and the Parmesan cheese.

Step 3

Cover and cook on Low for 6 hours or on High for 3 hours, until sweet potatoes are tender and mixture is hot and bubbly.