Begin by creaming 1 cup of unsalted butter and ½ cup of powdered sugar together in a large mixing bowl using an electric mixer on medium speed for about 3 minutes until light and fluffy. Add a pinch of salt (if using) and 1 teaspoon of vanilla extract, blending well for an additional minute until fully incorporated.

Gradually sift in 2 cups of all-purpose flour to the butter mixture, mixing on low speed until just combined. Be careful not to overmix; the dough should be smooth yet firm.

Shape the dough into a log, approximately 2 inches in diameter, and wrap it tightly in plastic wrap. Chill in the refrigerator for at least 1 hour; overnight is best.

Preheat the oven to 350°F (175°C) and line a baking sheet with parchment paper. Slice the chilled dough into rounds about ¼ inch thick and arrange them on the baking sheet with some space between each.

Bake for 12-15 minutes or until the edges are just golden. Remove from the oven and cool on the baking sheet for about 5 minutes before transferring to a wire rack to cool completely.