Preheat your oven to 350 degrees F.

Line a baking sheet with parchment and set aside.

In the bowl of a stand mixer, combine the sugar and softened butter. and beat at high speed until you have a creamy, smooth mixture.

Next, add in the eggs, vanilla and sour cream and mix them at medium speed until everything is well combined.

Then add in the baking soda, baking powder, salt and flour. Mix on low speed until combined.

Then stop the mixer and scrape down the sides - and repeat until your mixture is completely combined and you have a nice cookie dough.

Use a small ice cream scoop or teaspoon to scoop out the dough and make sure to place each cookie dough ball on the prepared baking sheets at least 2 inches apart. These Sour Cream Cookies will spread while cooking!

Bake in the preheated oven at 350 degrees F for 12-15 minutes, or until the edges are slightly browned.

Allow your Sour Cream Cookies to cool completely before decorating!

I recommend letting them sit on the baking sheet for at least 2 minutes before removing them a wire cooling rack to finish cooling completely. If you move them too soon, they will crumble and fall apart. If you do not have a cooling rack, allow them to cool on the baking sheet for at least 5 minutes.

For the frosting - in the bowl of a stand mixer, combine the softened butter, pure vanilla extract, milk and powdered sugar.

Then mix your dry ingredients on low speed until the mixture is smooth.

Then increase the speed to medium and mix for an additional minute, or until the frosting is light and fluffy.

Scrape down the sides and mix again.

Finally, transfer the frosting to a piping bag.

Once the cookies are cool, pipe a spiral of frosting on each one. Decorate with sprinkles, if desired.