Place flour, garlic powder, salt and pepper on to plate, stir. Dust chicken breasts on both sides in seasoned flour mixture. Heat olive oil on medium/low heat, in non stick skillet, add dusted chicken breasts. Cook chicken on both sides until golden brown (about 3-5 minutes each side), transfer to baking pan. Top each breast with 1/4 cup of marinara and 1 ounce slice of mozzerella. Bake for 15-20 minutes in a 375 degree oven, until golden and bubbly. While chicken is cooking, cook spaghetti according to package directions and heat remaining marinara in a saucepan. To serve, plate chicken with a side of spaghetti topped with hot marinara. Sprinkle with shredded parmesan cheese, if desired. Add a ceasar salad and chunks of crusty Italian bread with gourmet butter or an herb blend mixed with a really good extra virgin olive oil to finish out the meal. If you still have room, an expresso with either fresh fruit, tiaramisu, cannoli or gelato will complete your Italian feast.