Preheat your oven to 350°F (175°C) and line two baking sheets with parchment paper.
In a mixing bowl, cream together the room temperature butter and cream cheese until smooth and well combined.
Gradually mix in the powdered sugar until fully incorporated.
Sift together the cornstarch and flour, then gradually fold them into the wet mixture.
Drop teaspoonfuls of dough onto the prepared baking sheets, spacing them apart.
Bake for 10-12 minutes or until the edges are set, but the centers are still soft.
Let the cookies cool on the baking sheet for about a minute before transferring them to a wire rack.