Preheat your oven to 375°F (190°C) and grease a muffin tin.
In a large bowl, whisk together the flour, granulated sugar, baking powder, and salt.
In another bowl, combine the melted butter, milk, and vanilla extract. Pour the wet ingredients into the dry ingredients and mix until just combined.
Gently fold in the diced peaches and ground cinnamon until evenly distributed.
Spoon the batter into the prepared muffin tin, filling each cup about 2/3 full.
Sprinkle a little brown sugar on top of each cruffin for added sweetness and crunch.
Bake in the preheated oven for 20-25 minutes, or until the tops are golden brown and a toothpick inserted into the center comes out clean.
Allow the cruffins to cool in the pan for 5 minutes before transferring them to a wire rack. Dust with powdered sugar before serving.