In a large mixing bowl, whisk together the all-purpose flour, 1/2 cup of granulated sugar, baking powder, and salt. In another bowl, mix the melted butter, whole milk, eggs, and vanilla extract. Stir until smooth. Pour the wet ingredients into the dry ingredients and gently stir until just combined.

Take your greased muffin tin and divide the batter evenly among the cups, filling each about two-thirds full. Optionally, add chocolate chips or dulce de leche in the center before adding more batter.

Preheat your oven to 375°F. Bake for 18-20 minutes until golden brown. Check with a toothpick to ensure they are done. Let them cool in the tin for about 5 minutes.

Mix together the remaining 1/4 cup of granulated sugar and ground cinnamon. Brush the tops of the cruffins with melted butter and roll in the cinnamon-sugar mixture until well coated.