Start by patting your chicken breasts dry with a paper towel. Sprinkle both sides generously with salt and pepper for an even seasoning. This forms the foundation of your flavor.
Prepare three bowls for dredging. One should contain flour, another whisked eggs, and the third breadcrumbs. Dip each chicken breast in flour first, then egg, and finally coat it in breadcrumbs. This crispy breading will create that classic Parmesan crust.
Spread a thin layer of marinara sauce on the bottom of your Crock-Pot. Place the breaded chicken breasts over the sauce in a single layer to ensure even cooking.
Pour the remaining marinara sauce over the chicken. Then sprinkle shredded mozzarella and a generous amount of Parmesan cheese across the top. The cheese will melt and bubble into a golden crust as it cooks.
Cover your Crock-Pot and cook on low for 4–5 hours. Resist the urge to peek, as opening the lid reduces the cooking temperature. Your house will smell amazing as the chicken slowly absorbs the flavors.
Once done, serve your Crock-Pot Chicken Parmesan on a bed of spaghetti or zucchini noodles. Garnish with fresh basil leaves for a pop of color and fresh aroma.