01 - Preheat oven to 400°F or set toaster oven to medium-high.
02 - In a small bowl, mix granulated sugar, ground cinnamon, and optional salt until combined.
03 - Evenly spread softened butter over one side of each bread slice.
04 - Sprinkle the cinnamon-sugar mixture generously over the buttered side of each slice.
05 - Place bread slices, sugar side up, on a baking sheet and bake for 5 to 7 minutes until edges turn golden and sugar melts slightly.
06 - Remove from oven, allow to cool for 1 to 2 minutes, then serve warm.