Whisk the eggs and the milk together with the cinnamon, vanilla extract and sweetener/sugar in a wide shallow bowl. Spread 1 teaspoon of the Nutella or Hazelnut spread onto each slice and sandwich them together to make 2 sandwiches. Soak the sandwiches in the egg wash. Heat a nonstick pan/skillet with 1 teaspoon butter. Fry the egg-soaked sandwiches on low - medium heat on both sides until golden.Sprinkle the cinnamon sugar (or cinnamon sugar mix) onto a small plate and press the French Toast sandwiches down until coated like a Churro or a sugared donut.Serve with 1 scoop frozen yoghurt, ice cream, fruit, berries, and/or more nutella!Drizzle alllll over your Donut French Toasts!!