In a mixing bowl, combine cream cheese, brown sugar, and cinnamon until smooth. Stir in chocolate chips if using.

Transfer the filling to a piping bag or a plastic bag with the corner snipped off.

In a small bowl, mix granulated sugar and cinnamon together until well combined.

In a large bowl, whisk together eggs, milk, vanilla extract, and salt until well blended.

Take a slice of bread, pipe a generous amount of churro filling in the center, and top with another slice of bread to create a sandwich.

Heat butter on a griddle over medium heat. Dip each sandwich in the egg mixture, ensuring both sides are coated.

Cook each sandwich for about 3-4 minutes on each side, until golden brown.

Immediately after cooking, coat each sandwich in the cinnamon sugar mixture.

Slice the stuffed French toast in half and serve warm, optionally with syrup or whipped cream.