Trim and roll the bread flat.

Spread the chocolate sauce on each slice of the bread

And tightly roll up each bread slice.

In one shallow bowl, mix together the milk, egg, sugar, and vanilla with a whisk. In a second shallow bowl, combine the sugar and cinnamon.
Heat a large nonstick skillet over medium heat and add the butter until it melts.

Dip and fully coat each of the rolled-up slices of bread in the milk and egg mixture. Place the custard-coated rolls into the heated skillet and cook turning as necessary until they are slightly crisp and golden brown on all sides, about 2 minutes. Continue until all of the rolls are cooked. Immediately after removing each slice of bread from the skillet, roll them in the cinnamon and sugar mixture to fully coat.

Serve warm.