Place 1 cup softened unsalted butter, 1/4 cup granulated sugar, 1/2 teaspoon vanilla extract, and 1/2 cup powdered sugar into a large mixing bowl and beat it on high speed using an electric hand mixer. Mix until the butter becomes light and whipped (about 1-2 minutes)
Now add in 2 cups all-purpose flour, and a pinch of salt. Mix the cookie dough together on low speed until it begins to come together. It will look crumbly but should form shape once your hands compress it
Form the shortbread dough into a ball and place it on top of a sheet of parchment paper. Then press it down and place another sheet of parchment paper on top.
Now use a rolling pin to flatten out the dough to about 1/4-1/2 inches thick.
Remove the parchment paper from the top and begin cutting out circles or desired shape. If you don’t have a cookie-cutter, you can use a glass cup to cut out the circles.
Preheat your oven to 325°F and bake the shortbread cookie for about 12-14 minutes. Allow the cookies to cool on the hot baking sheet for about five minutes before transferring to a cooling rack. 
You can leave them as they are or dip them in melted semisweet chocolate and garnish with chopped roasted salted pistachios. This makes them look extra fancy and looks great on a cookie platter.
Notes
How to Store these Classic CookiesTo store these delicious shortbread cookies, you can leave them at room temperature in an airtight container for about 1 week. If you prefer to refrigerate them, then they will last for about 10 days.