Preheat oven to 400 degrees Fahrenheit.

Spray an 8x4 inch loaf pan with cooking spray.

In a bowl, mix together Bisquick, egg white, water, and garlic powder until well combined.

Spread the batter evenly into the prepared loaf pan.

In a nonstick skillet, cook diced bell pepper and chopped onion over medium-high heat, stirring frequently until the onion becomes tender.

Stir in the diced chicken breast, canned Italian-style diced tomatoes, and Italian seasoning into the skillet. Heat through.

Spoon the chicken and tomato mixture evenly over the batter in the loaf pan.

Sprinkle shredded reduced-fat mozzarella cheese over the top.

Bake in the preheated oven for 20-23 minutes, or until golden brown.

Loosen the pizza bake from the sides of the pan before serving.