In a mixing bowl, combine the room temperature butter and brown sugar until well blended.
Add the eggs, vanilla, and milk to the mixture, whisking until smooth.
Stir in the cinnamon powder until evenly distributed.
Heat a skillet over medium heat and lightly grease it.
Dip slices of bread into the batter, ensuring they are well coated.
Place the coated bread slices onto the skillet and cook until golden brown on both sides.
Serve warm, optionally with syrup or powdered sugar.
