Preheat the oven to 375°F (190°C). 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 melted butter, milk, eggs, and vanilla extract. Mix well.
Pour the wet ingredients into the dry ingredients and stir until just combined. Do not overmix.
Gently fold in the cherries.
In a small bowl, mix the brown sugar and cornstarch together.
Spoon the muffin batter into the prepared muffin tin, filling each cup about two-thirds full. Sprinkle the brown sugar mixture evenly over the tops of the muffins.
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.