Preheat the oven to 350 degrees Fahrenheit and prepare your baking sheets by lining them with nonstick baking mats or lightly spraying them with nonstick baking spray.

In the bowl of an electric mixer, cream together softened butter and sugar until fluffy.

Add the egg and mix until incorporated.

Add vanilla and sour cream and mix until all the way incorporated.

In a separate bowl, whisk together flour, baking soda and salt. Add the flour mixture to the wet mixture and mix just until incorporated.

Scoop or form dough into 1 1/2" balls and place at least 2" apart on prepared baking sheets.

Press the dough balls down with the palms of your hands to flatten.

Bake for 7-8 minutes. Be careful not to over bake!

Allow the cookies to cool on the baking sheets for a few minutes before carefully removing them to cooling racks to cool completely.

For the frosting, cream together softened butter, powdered sugar, vanilla, and just enough milk for thinning. I start by adding a few Tablespoons and mixing, then adding a Tablespoon at a time, and mixing in between, just until the frosting is light and fluffy. Allow it to mix on a high speed for 5 minutes to get really fluffy and amazing! Add food coloring, if desired.

Frost the cooled cookies and decorate with sprinkles or other candies. Enjoy!

Store in an air tight container to keep them soft.