Cream the Butter and Sugar: Beat the softened unsalted butter and powdered sugar together until smooth and creamy, about 2-3 minutes.

Add Flavorful Ingredients: Mix in the lemon zest, lemon juice, and vanilla extract until well combined, about another minute.

Combine Dry Ingredients: Slowly add flour, cornstarch, and sea salt while mixing on low speed until just incorporated, avoiding overmixing.

Form the Dough Logs: Divide the dough into two portions and shape into logs, wrap in wax paper, and chill for at least one hour.

Preheat the Oven: Preheat to 350°F (175°C) and line a baking sheet with parchment.

Slice the Chilled Dough: Unwrap and slice logs into 12 pieces each, about 1-inch thick, and arrange on the baking sheet.

Bake the Cookies: Bake for 12-14 minutes until edges are lightly golden, ensuring they remain soft.

Cool and Roll in Sugar: Cool cookies for 5 minutes before gently rolling in powdered sugar.