Preheat a skillet or griddle over medium heat.
In a medium bowl, whisk together eggs, milk, vanilla, cinnamon, pumpkin pie spice, brown sugar, and pumpkin puree until smooth.
Melt 1 tablespoon of butter on the preheated skillet, spreading it to cover the surface.
While the butter melts, dip a slice of bread into the pumpkin mixture, coating both sides well.
Place the coated bread on the skillet. Repeat with 1-2 more slices, depending on the size of your pan.
Cook each slice for 2-3 minutes until golden brown, then flip and cook for another 2-3 minutes on the other side.
Transfer cooked slices to a plate and cover to keep warm.
Repeat the process with remaining bread and pumpkin mixture, adding 1 tablespoon of butter between batches.
Serve warm with syrup, cinnamon-sugar, or powdered sugar as desired.