Preheat the oven to 300ºF and prepare two cookie sheets with parchment paper.
In a stand mixer or large mixing bowl with electric beaters, beat the butter and powdered sugar on high for 5 minutes. Scrape down the sides of the bowl when necessary.
Add in the vanilla extract and mix on high for another 2 minutes.
Measure in the flour, cornstarch, and salt and mix on low until combined.
Turn the mixer up to high and allow it to beat for 2 minutes.
Portion the dough with a 1.5 tablespoon scoop and, with hands lightly dusted with powdered sugar, roll into balls and place on the prepared cookie sheets. Gently press each cookie ball with a fork lightly dusted with powdered sugar and top with sprinkles if desired.
Bake for approximately 15-20 minutes or until the edges are just set. Allow the cookies to fully cool on the sheets. Enjoy!
Store at room temperature in an airtight container for up to 5 days or frozen for up to 6 months.
