Measure out and sift powdered sugar into a bowl so it's ready to go. Prep a cookie sheet by lining it with parchment paper.
Add softened cream cheese to a mixing bowl or the bowl of a stand mixer and beat until it's light and fluffy. It's really important to make sure the cream cheese is completely softened, so it incorporates smoothly.
Beat in the peppermint extract -- it's easier to add it first into the cream cheese than when the mixture is thicker.
Add powdered sugar one cup at a time, making sure it's mixed really well before the next.
You should be able to roll the mixture into balls and not be really sticky. If it is, you can add a little more powdered sugar at a time-- until it's at that consistency.
Roll mixture into small balls, laying them out on the cookie sheet. Press them down with your thumb or forefinger, then immediately press in the sprinkles.
Cover the cookie sheet with plastic wrap, then refrigerate for at least 3 hours, but up to 24 hours. They'll be firm on the outside, and soft on the inside!