DIRECTIONS Preheat oven to 340˚F (170˚C). Line two baking sheeting with parchment paper.Place butter, vanilla extract and sugar in a large bowl, beat until incorporated, light and fluffy.Sift in flour, cornstarch, cocoa powder in two batches. Mix until combined.Transfer the dough to a piping bag fitted with a large open star tip. Pipe the dough into 2-inch circles.Refrigerate for 20-30 minutes.Bake, one pan at a time, for about 13-15 minutes. Allow to cool completely before storing or serving.Notes:Store in an airtight container at room temperature for up 3-4 days.You can freeze the cookies for up to a month.OTHER COOKIE RECIPES:Thumbprint CookiesCream Cheese CookiesSoft and Chewy Chocolate Chip CookiesAlmond Cookies