Preheat your oven to 350°F (175°C) and line a baking sheet with parchment paper.

In a large mixing bowl, cream together the softened unsalted butter and granulated sugar using an electric mixer until light and fluffy, about 3-5 minutes.

Add the pure vanilla extract and mix on low speed until fully incorporated.

Gradually add the all-purpose flour into the butter mixture, mixing on low speed or gently folding until just combined.

Shape the dough into a log approximately 2 inches in diameter, wrap tightly in plastic wrap, and chill in the refrigerator for at least 1 hour.

Slice the chilled log into rounds about 1/4-inch thick and arrange them on the prepared baking sheet.

Lightly sprinkle each cookie round with flaky sea salt and bake for 12-15 minutes until golden around the edges.

Allow the cookies to cool on the baking sheet for about 5 minutes before transferring them to a wire rack to cool completely.