01 - Preheat oven to 350°F (175°C). Grease a mini round cake pan or muffin tin.
02 - In a large mixing bowl, cream together room temperature butter and granulated sugar with an electric mixer until light and fluffy.
03 - Add eggs, vanilla extract, and sour cream to the creamed mixture. Mix until fully integrated.
04 - In a separate bowl, whisk together all-purpose flour, baking powder, cornstarch, and salt.
05 - Gradually add dry ingredients into the wet mixture, mixing until just combined. Set dough aside.
06 - In another bowl, blend melted butter and light brown sugar until smooth.
07 - Spoon about 1 tablespoon of the brown sugar mixture into each cavity of the prepared pan, spreading evenly.
08 - Place a pineapple slice over the brown sugar glaze. Position a maraschino cherry in the center of each pineapple ring.
09 - Using a 3-tablespoon scoop, portion cookie dough over each fruit-topped cavity. Gently flatten the dough with an offset spatula.
10 - Bake for 25 minutes, or until the cookies are golden around the edges and the brown sugar is bubbling up the sides.
11 - Cool for 10 minutes, then carefully invert cookies onto wax paper to allow brown sugar glaze to run over the tops.
12 - Allow cookies to cool completely before serving. Store in an airtight container.