Cream the butter and sugar: In a large mixing bowl, beat softened butter and sugar together with a hand or stand mixer until light and fluffy, about 2–3 minutes.

Add vanilla extract and mix until well combined.

Combine dry ingredients: In a separate bowl, whisk together flour, cornstarch, and salt.

Gradually add the dry mixture to the butter mixture, mixing on low speed until the dough just comes together. Do not overmix.

Shape the dough into a disk, wrap it tightly in plastic wrap, and refrigerate for 30 minutes to firm up.

Roll and cut: On a lightly floured surface, roll the dough to about ¼-inch thickness. Use a cookie cutter to cut into desired shapes and transfer to a parchment-lined baking sheet.

Bake: Bake at 350°F (175°C) for 12–15 minutes, or until the edges are lightly golden. Let cookies cool on the sheet for 5 minutes before transferring to a wire rack to cool completely.

Prepare the chocolate drizzle: In a microwave-safe bowl, combine chocolate chips and oil. Heat in 20-second intervals, stirring until smooth.

Drizzle or dip cooled cookies in melted chocolate and place on parchment paper to set.

Let chocolate harden before storing or serving. Enjoy your buttery, crisp, and perfectly sweet shortbread cookies!