In a mixing bowl, whisk together the flour, cornstarch, baking soda and salt until well combined. Set aside.
In a large mixing bowl, cream together the butter and cream cheese with a hand held mixer or stand up mixer until light and fluffy (approximately 3-5 minutes).
Add in the sugar, eggs and vanilla extract. Mix until combined.
Reduce the mixer speed until low. Then gradually add the dry ingredients into the wet ingredients until just combined.
Cover the dough and refrigerate it for 1-2 hours.
Preheat the oven to 350 degrees Fahrenheit.
Place the sprinkles in a shallow bowl. Spoon the dough into approximately 1 tablespoon size balls and roll the balls in the sprinkles until they are completely covered.
Then place on a baking sheet approximately 2 inches apart.
Bake for 9-12 minutes until the cookies are set but not browned. Remove from the oven and let the cookies sit on the baking sheet for 5-10 minutes.
Move the cookies from the baking sheets to a wire rack to cool completely.
Then the cookies are ready to serve and enjoy!