In a large bowl using an electric hand mixer or using a stand mixer fitted with the paddle attachment, beat 1 cup butter on medium high speed until light and fluffy (2-3 minutes).
Then add ½ cup confectioner’s sugar and ¼ cup granulated sugar and continue beating until fluffy (2-3 minutes). You’ll want to start slow and work your way up to medium speed. Remember to scrape the bottom and sides of your bowl with a spatula.
Transfer cookie dough into your prepared pan and firmly and evenly press the dough onto the bottom using your fingers (see notes).
To prevent your shortbread from puffing up and to allow the cookie to cook evenly, dock the dough with a skewer or a small fork. Dock the dough evenly, at about 1-inch intervals (see notes).
Bake your shortbread for 20-25 minutes or until the edges turn a light brown (do not over bake, shortbread should be pale and light).
Allow the shortbread to cool in the pan for 10 minutes then cut into rectangles or squares or triangles, up to you! To store, place the completely cool cookies in an airtight container on the counter. They should keep for up to 2 weeks.
The yield/number of cookies depends on how big/small and what shape you cut your cookies.
The cookie dough will be a little crumbly but should be fairly easy to handle. If your fingers get a little sticky when pressing it onto the pan, wet your fingers with a little water or dust them with a little flour.
In addition to docking, I also like to lightly score my dough with my bench scraper so I know where to cut them once they’re baked, but it’s not necessary.
See the post for more baking tips and the complete step-by-step photos.