These buttery Irish shortbread cookies are easy to bake and taste delicious.

The most important ingredient in this simple, four-ingredient recipe is the butter. Choose the best butter you can find will make the tastiest shortbread. We recommend using Irish butter (Kerrygold's Pure Irish Butter is great) - salted or unsalted. Grass-fed cows, especially during the spring and summer months, produce milk high in butterfat which, when processed, forms creamy yellow butter. Irish butter is grass-fed and comes in two formats - salted or unsalted.

You can make these Irish shortbread cookies with your usual brand of butter and they'll be delicious too. But if you want absolutely delicious shortbread, be sure to use Irish butter.

Our tips for baking these Irish shortbread cookies

• If you don't have a mixer dough hook, the butter needs to be very soft. Allow the butter to come to room temperature by letting it sit out overnight. If you're short on time, place your butter in a small bowl and put it in the microwave at the lowest power level (usually 10 which is 10% of maximum power). Start with 30-second increments. You just want to get the butter nice and soft, but not melted.
• You'll see in the recipe that you need to chill the mixture for 30 to 45 minutes before baking. The chilling helps them keep their shape in the hot oven. Also, chilling the cookies, uncovered, helps them to dry out a bit which is a good thing with shortbread, as it intensifies the flavor.
• The cornflour (corn starch if you're in the U.S.) helps the shortbread to keep its shape in the oven and adds to the crisp texture.
• Use a rolling pin to roll the shortbread to a 7mm (¼-inch) thickness. Here are some tips on rolling and cutting out cookies:
• Keep your work surface and rolling pin dusted with flour.
• Between each cookie, rub the cutting edge of your cookie cutter in a little flour.
• Press firmly when cutting out the cookies. Don't twist the cookie cutter as the shape will get distorted.
• You can use the scraps to reroll and cut more cookies.
• It’s fine to reroll the scraps and cut more cookies.
• After being in the oven for up to 35 minutes, the cookies will be slightly puffed. That's why we recommend allowing the shortbread to cool inside the oven for a few minutes before transferring them. Once you take them out of the oven, give them a nice flat top by pushing gently on the tops with a metal spatula.