Crock-Pot Ravioli Casserole Crock-Pot Ravioli Casserole Advocate staff photo by HEATHER MCCLELLAND -- Prepare your mom or grandmother a Mother's Day meal that includes easy-to-make Crock-Pot Ravioli Casserole. Katherine Hert June 05, 2013 Comments ADVOCATE-TESTED RECIPE Crock-Pot Ravioli Casserole Serves 4 to 6. Recipe is by Katherine Hert. 1½ lbs. lean ground beef 1 onion, chopped 1 clove garlic, minced 1 (15-oz.) can tomato sauce 1 (14.5-oz.) can stewed tomatoes 1 tsp. oregano 1 tsp. Italian seasoning Salt and pepper to taste 1 (10-oz.) pkg. frozen spinach, thawed, or 1 (9-oz.) pkg. fresh spinach 1 (16-oz.) pkg. bow-tie pasta, cooked ½ cup Parmesan cheese, shredded 1½ cup mozzarella cheese, shredded 1. Brown ground beef with onion and garlic on stove-top over medium-high heat. 2. Place in slow cooker and add sauce, tomatoes and seasonings. 3. Cook on Low for 6 to 7 hours. Add spinach, pasta, Parmesan and 1 cup of the mozzarella cheese during the last 30 minutes of cooking and turn cooker to High. 4. Add last ½ cup of mozzarella in the last few minutes, allowing to melt on top.