In the bowl of a stand mixer with the paddle attachment or in a large mixing bowl combine the butter and the sifted powdered sugar. Mix on low speed until the powdered sugar combines with the butter and then increase the speed to medium high for about 1 minute.
1 cup butter, salted, 1 cup sifted powdered (confectioner's) sugar
Scrape down the sides of the bowl and mix on high speed until the butter and sugar have lightened in color and the mixture is light and airy. This takes about 1-2 minutes. Scrape the sides of the bowl. Add the vanilla extract and mix until incorporated. Scrape the sides of the bowl again.
1 teaspoon vanilla extract
Add about ⅓ of the flour and mix on low speed until incorporated. Add another ⅓ of flour and mix until incorporated. Add the remaining flour and mix until incorporated.
Assemble the pastry bag with a large open star tip and fill the bag about ½ way with the cookie dough. Pipe small circles about 2" in diameter onto the cookie sheet pan about 2" apart. OR, use a small scoop or Tablespoon and place each scoop about 2" apart, then press down to create a round disc.
Bake at 350℉/175℃ for 12 minutes or until the edges of the cookies just start to turn golden brown. Remove from the oven and let them cool on the tray for about 5 minutes. Transfer the cookies to a wire rack and let them cool completely.
The amount of cookies you will get from a batch will depend on how big you make them. I usually get around 40 cookies when I pipe out 2" circles using an open star tip. Lining your cookie tray with parchment or a silicone mat will result in softer cookies.
Storage
Once completely cooled store the cookies in an airtight container at room temperature for up to a week or freeze in an airtight container for up to 6 months.