Separate the egg yolks from the whites in a small bowl and set aside.
Next, in a large bowl, add the egg yolks, whole egg, milk, brown sugar, vanilla extract, cinnamon, and salt. Whisk until combined.
Place the cinnamon Chex cereal in a ziploc bag and crush it with a rolling pin or a large wooden spoon. Keep smashing until the cereal is into small crumbs, similar to panko breadcrumbs.
Pour the egg mixture into a shallow dish like a pie plate. In another dish, pour the crushed cereal into a shallow dish.
Dip both sides of the bread into the egg mixture for two seconds. Then, place the egg-soaked bread in the cereal crumbs, gently pressing the crumbs into the side of the bread.
Place the cereal-coated bread onto the cooking surface.
Blackstone Method: Preheat to medium heat and place the uncooked French toast on the griddle. Use a large metal spatula to flip the french toast after 3-5 minutes, or the outside is golden brown. Cook the other side until golden brown. Serve immediately.
Frying Pan/Griddle Stovetop Method: Melt a tablespoon of salted butter or coconut oil over medium-low heat in a large frying pan. Place the uncooked French toast in the pan. Turn up to medium high heat and cook it until golden brown. This will take 3-5 minutes. Flip and cook the French toast for the same amount of time. Remove and serve immediately.
If cooking in advance, place the cooked French toast on a cooling rack on a baking sheet in a warm oven. I like to set the oven to 170 degrees F to keep it warm but not cook anything.
Notes
Store in an airtight container. Reheat over low heat in a skillet until warm. Freeze chilled leftovers in a Ziplock bag with parchment paper in between.