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

In a large bowl, whisk together the flour, granulated sugar, baking powder, salt, and cinnamon.

In another bowl, combine the milk, melted butter, egg, and vanilla extract.

Pour the wet ingredients into the dry ingredients and stir until just combined, being careful not to overmix.

In a small bowl, toss the cherries with brown sugar and cornstarch until well coated.

Gently fold the cherry mixture into the muffin batter.

Spoon the batter into the prepared muffin tin, filling each cup about ¾ full.

Bake for 20-25 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.