01 - Spread 1 tablespoon of creamy peanut butter evenly on each of 4 slices of bread.
02 - Top the peanut butter with 1 tablespoon chocolate hazelnut spread or a tablespoon of semisweet chocolate chips on each prepared slice.
03 - Place a plain slice of bread over each assembled half to form 4 filled sandwiches.
04 - In a shallow bowl, whisk together eggs, whole milk, granulated sugar, vanilla extract, ground cinnamon, and a pinch of salt until fully combined.
05 - Heat a large non-stick skillet or griddle over medium heat and melt 1 tablespoon of unsalted butter.
06 - Dip each sandwich into the egg mixture, ensuring all sides are thoroughly coated without soaking through the bread.
07 - Place egg-coated sandwiches onto the preheated skillet. Cook 3 to 4 minutes per side, until golden brown and the filling is melted, adding remaining butter as needed.
08 - Remove sandwiches from the skillet, slice in half, and serve warm with desired toppings such as powdered sugar, fresh berries, or maple syrup.