Preheat oven to 350 degrees. Set aside the USA pan mini round cake pan.
In a large mixing bowl, add in the butter and sugar and mix until light and fluffy.
Add in the eggs, vanilla extract, and sour cream and mix until combined.
Add in the flour, baking powder, cornstarch, and salt. Mix until the cookie dough just comes together. Set aside.
In a separate bowl, stir together the melted butter and brown sugar until combined.
Add about a tablespoon of the brown sugar mixture into the bottom of each cavity. Spread it around to cover the bottom.
Add the pineapple slice on top of the brown sugar and the cherry in the center of the pineapple.
Add a 3 T. cookie scoop of cookie dough to the top. Using an offset spatula, flatten it out.
Place into the oven and bake for 25 minutes or until the edges are golden brown and the brown sugar is bubbling up the sides.
Let cool for 10 minutes and then turn out onto a wax paper covered surface. Brown sugar will run all over, so the wax paper is necessary. If the pineapple sticks to the pan, just reposition it back on the cookie.
Let cool completely before eating. Store in an airtight container. These are best if ate within the first 2 - 3 days.