This recipe is less fussy AND less messy than your typical French toast recipe.
HEAT AND GREASE: Adjust 1 oven rack to lowest position and second rack 5 to 6 inches from broiler element. Heat oven to 425 degrees. Spray baking sheet well with vegetable oil spray.
WHISK: In large bowl, whisk eggs, vanilla, brown sugar, cinnamon, and salt until well combined and sugar is dissolved, about 30 seconds. Add milk and melted butter and whisk until combined.