Oven method:

1. Preheat your oven to 350°F (175°C).
2. In a small bowl, mix together the softened butter, sugar, cinnamon, and vanilla extract (if using) until well combined.
3. Spread the cinnamon butter mixture evenly on one side of each bread slice.
4. Place the bread slices, butter side up, on a lined baking sheet.
5. Bake for 8-10 minutes or until the edges are golden brown and the cinnamon sugar has melted.
6. Allow the toast to cool slightly before serving.

Stovetop method:

1. In a small bowl, mix together the softened butter, sugar, cinnamon, and vanilla extract (if using) until well combined.
2. Spread the cinnamon butter mixture evenly on one side of each bread slice.
3. Heat a non-stick skillet or griddle over medium heat.
4. Place the bread slices, butter side down, onto the heated skillet or griddle.
5. Cook for 2-3 minutes or until the edges are golden brown and the cinnamon sugar has melted.
6. Carefully flip the bread slices and cook for an additional 1-2 minutes.
7. Remove the toast from heat and serve immediately.