Smashed Avocado and Tomato Bruschetta

Nonstick cooking spray 1/2 loaf French bread (or 1 petite loaf), cut into 1/2-inch slices 1 pint cherry or grape tomatoes, halved 1 clove garlic 2 Tablespoons olive oil 1 Tablespoon balsamic vinegar 2 avocados, smashed Salt and pepper, to taste