Preheat the oven to 350°F.
Cream together the butter and granulated sugar in a mixing bowl until light and fluffy.
Add the eggs, vanilla extract, and sour cream; mix until well combined.
Combine the dry ingredients by incorporating flour, baking powder, cornstarch, and salt into the wet ingredients.
Mix the brown sugar and melted butter in a separate bowl until combined.
Spoon the brown sugar mixture into the bottom of each mini round cake pan cavity.
Place a drained pineapple slice on top of the brown sugar mixture in each cavity.
Add a maraschino cherry in the center of each pineapple slice.
Scoop the cookie dough onto each pineapple and cherry.
Bake for 25 minutes until golden brown.
Cool for 10 minutes before inverting the cookies.
Let cool completely before serving.