Coat chicken in egg wash, dip into cheese and press cheese onto chicken. Move carefully to the bread crumb/cracker mixture and coat with crumbs. Place in prepared baking pan. Repeat until all chicken is coated.
Drizzle lightly with olive oil. Bake at 400 degrees for 30-40 minutes, or until chicken is cooked through and no longer pink.
While chicken is baking, prepare sauce by melted butter in a large pan. Add the flour and whisk to eliminate any lumps. Cook over medium-low heat for 2-3 minutes.
Add salt, pepper, and garlic salt to taste. Add 1 tsp dried parsley and 1/4 tsp sage.
Add hot water, condensed chicken base, and Marsala to the sauce pan and cook until mixture is thickened. Add the heavy cream and sour cream and stir to combine.