In a small bowl, use a fork to mix the granulated sugar with the strawberry slices and set aside for about 15 minutes. (Note: This will macerate the strawberries, intensifying the flavor and softening their texture.)
In a large bowl, with a hand or stand mixer, beat the cream cheese and powdered sugar together until smooth. Gently fold in the strawberries.
In a separate large bowl, beat the eggs, milk, vanilla extract, and cinnamon.
Melt ⅓ of the butter in a large, heavy bottom, skillet over medium high heat. While the butter is melting, lay a slice of bread on a flat surface and spread a generous amount of the cream cheese filling over it. Place a second slice of bread over it. Repeat until you have 3 “sandwiches.”
Soak each sandwich in the egg mixture for about a minute making sure each side is fully coated in the mixture. Immediately transfer the sandwich to the skillet and cook for about 5 minutes, using a spatula to flip halfway through, or until each side is golden brown.
Serve warm with your toppings of your choice.