Preheat your oven to 375°F (190°C) and line a muffin tin with paper liners or grease it with cooking spray.

In a large mixing bowl, whisk together the flour, granulated sugar, baking powder, baking soda, salt, and cinnamon (if using).

In another bowl, combine the melted butter, buttermilk, eggs, and vanilla extract. Mix until well combined.

Pour the wet ingredients into the dry ingredients and stir until just combined. Be careful not to overmix; a few lumps are okay.

Gently fold in the cherries until evenly distributed throughout the batter.

Divide the batter evenly among the muffin cups, filling each about 2/3 full.

In a small bowl, mix the brown sugar with a pinch of cinnamon, then sprinkle this mixture over the tops of the muffins.

Bake in the preheated oven for 18-20 minutes, or until a toothpick inserted into the center comes out clean.

Allow the muffins to cool in the pan for 5 minutes before transferring them to a wire rack to cool completely.