Spread the olive oil into the bottom of your crock pot.
Beat the egg with a fork in a separate bowl.
Mix the bread crumbs with the seasonings and the grated Parmesan cheese in another separate dish.
Dip the chicken into the egg, then into the bread crumb mixture, coating both sides with crumbs, cheese and seasonings. Place the chicken breast pieces in the bottom of the crockpot.
Layer half of the shredded mozzarella cheese on top (about 3/4 cup of shredded cheese).
Cover chicken and cheese with entire jar of marinara sauce. Close lid and cook on low for 4-5 hours or high for 2-3.
About 30 minutes before serving, sprinkle remaining shredded mozzarella cheese and Parmesan cheese over top of sauce and place the lid back on top of the slow cooker to let it finish cooking and allowing cheese to melt.
Top with chopped fresh basil and serve over cooked pasta.
Notes
This recipe uses Italian bread crumbs to help season the chicken. However, if you only have plain bread crumbs you can make those work. No need to run out to the grocery store just to get seasoned bread crumbs.
Try salting the chicken breasts before coating them with egg and the bread crumbs for a little bit of extra oomph