Preheat oven to 350, and line a baking sheet with parchment paper
Beat butter and both sugars together until smooth and creamy
Add in the egg yolk and vanilla and mix to combine
Mix in flour, baking soda, and salt until just combined
Fold in sprinkles, but do not overmix
Roll the dough into 3 balls and place on prepared baking sheet
Bake for 10-15 minutes until the edges of the cookie are golden brown (leave in slightly longer for a less gooey cookie)
Remove from oven and let cool on the baking sheet for 5 minutes. Finish cooling on a cooling rack.
Note:
Cookies can be stored in an airtight container for up to 5-7 days before they start to get dry!
If you are using cold butter instead of room temp, we recommend melting in microwave for about 7-10 seconds to get it a bit soft. This makes it easier to beat with the sugar if you are using a whisk.
Recipe was prepared for Rodelle by Shelby Jenkins at @gooey.in.the.middle. Photos taken by Kathryn Herndon at @kniftykat