Using a handheld mixer (or a stand mixer with the paddle attachment), cream butter and sugar together until light and fluffy. This usually takes about 1 minute.
1 cup unsalted butter, 1 ½ cups white granulated sugar
Pour in vanilla and milk. Using a hand mixer, mix until combined. Scrape down the sides with a silicone spatula.
1 teaspoon vanilla, 7 tablespoons whole milk
Pour in half of the dry ingredients. Mix together. (I typically mix using a silicone spatula.) Pour in second half of dry ingredients and mix until the ingredients are incorporated. Try not to overmix as this will create dense cookies.
Cover and chill in refrigerator for an hour. This will help the cookies hold their shape and produce the taller, chewier texture.
Preheat oven to 350 degrees and line a baking sheet with parchment paper.
With a small cookie scoop or a tablespoon, scoop out dough. Then roll into a ball. Place dough balls spaced evenly on the parchment paper.
Bake 11-13 minutes. You are looking for the edges of the cookies to be formed and the center of the cookie to not be doughy. Try to not overbake! The cookies will continue to set while cooling.
Allow to cool for 3-4 minutes on the baking sheet then transfer to a cooling rack.
How to make the vanilla frosting
Add softened butter to a large bowl.
1 cup unsalted butter
Using a hand mixer on low speed, beat the butter until light and fluffy. This typically takes about 1 minute, and I pause halfway through to scrape down the sides of the bowl.
Pour in milk and vanilla and stir together.
1 teaspoon vanilla, 2 tablespoons milk
Pour in powdered sugar. Using hand mixer, mix until well combined.
3 cups powdered sugar
Spread on top of cookies and top with sprinkles if desired!
OPTIONAL: Sprinkles
Video
Notes
Oven temperatures can vary greatly. Check the cookies at 11 minutes and add time as needed. Don't skip the chill time, it will produce taller and fluffier cookies.View the step-by-step pictures above or the video for helpful visuals.