In a small bowl, combine the softened butter, brown sugar, and cinnamon. Mix until smooth and well combined.
Spread the cinnamon butter evenly over one side of two slices of bread. Place the remaining slices on top to create two sandwiches.
In a large shallow bowl, whisk together the eggs, whole milk, vanilla extract, and cinnamon until smooth.
Melt the butter in a skillet over medium-low heat.
Dip one sandwich into the egg mixture, coating both sides. Don't let the bread sit in the custard too long or it can become soggy.
Place the soaked bread in the skillet and cook over medium-low heat until golden brown, about 3–4 minutes per side. Flip carefully and cook the other side until golden and the center is warmed through.
While the French toast cooks, whisk together the softened cream cheese, powdered sugar, and milk until smooth. If the mixture is too thick to pipe, add a small splash of milk.
Transfer the cream cheese mixture to a small piping bag or Ziploc bag. Snip off a small corner.
Remove the French toast from the pan and drizzle or pipe the cream cheese topping over the top. Serve warm and enjoy!