Southern Corn Bread Dressing Squares

Ingredients

• 3 1/2 tablespoons melted butter, divided
• 3 cups corn bread dressing mix or crumbled corn bread
• 2 1/2 cups unsalted chicken stock
• 1 1/2 cups toasted and crumbled day-old bread
• 1 cup herb stuffing cubes
• 1 cup finely chopped yellow onion
• 4 1/2 tablespoons olive oil
• 1/4 cup finely chopped celery
• 1 1/2 teaspoons poultry seasoning
• 1/2 teaspoon freshly ground black pepper
• 1/4 teaspoon kosher salt
• 2 large eggs
• 1 large egg yolk
• Cooking spray