Preheat oven to 350°F. Grease a muffin tin with nonstick spray.
Add 1 teaspoon of melted butter and 1 teaspoon of brown sugar to each muffin cup.
Place a maraschino cherry in the center of each cup and top with a spoonful of crushed pineapple.
In a large bowl, mix sugar, sour cream, egg, and vanilla until smooth.
Add flour, baking powder, baking soda, and salt. Stir until just combined.
Spoon batter evenly over the pineapple in each muffin cup.
Bake for 20-22 minutes, or until a toothpick comes out clean.
Cool for 5 minutes, then invert onto a wire rack and let cool completely.