Slice each piece of brioche bread along the bottom, making sure to not cut all the way through the bread. Just create a pocket in the bread.
Add the mascarpone cheese, pumpkin puree, maple syrup, and pumpkin pie spice to a bowl. Mix until combined. Transfer to a piping bag or Ziploc bag with a corner cut off. Pipe about 2 tbsp of filling into each slice of bread.
In a shallow bowl, whisk together the eggs, milk, pumpkin pie spice, and vanilla. Quickly dip a piece of stuffed bread in the egg mixture, coating both sides. Immediately transfer to a greased pan over medium heat. Cook for 1-2 minutes per side, until golden brown.
Top with maple syrup and pecans and enjoy!