Deep-Dish Pizza

1 cup ricotta cheese

2 tablespoons snipped fresh flat-leaf parsley

2 13.8-ounce package refrigerated pizza dough

2 cloves garlic, minced

1 10-ounce package frozen chopped spinach, thawed and well drained

1/4 teaspoon crushed red pepper

1 1/4 cups shredded pizza cheese (4-cheese blend) (5 oz.)

Nonstick cooking spray

1 1/2 cups sliced red onion

1/4 cup olive oil