Add eggs to a shallow dish like a pie pan. Whisk until combined. Then add milk, cinnamon, vanilla, and brown sugar. Stir until combined.
Heat a skillet over medium heat and spray with cooking spray. Dip one slice of bread, front and back, in the egg batter. Once both sides are covered, place the slice in the pan. Repeat with each slice of bread.
Cook the slices until both sides are golden brown. Serve immediately with your favorite toppings.