In a large bowl, whisk ½ cup of melted and cooled unsalted butter, 1 large egg, and 2 teaspoons vanilla extract. Add the contents of the jar and gently stir with a wooden spoon or rubber spatula until combined (dough will be crumbly). Chill for 30 minutes.
Form golf ball sized portions of dough, pressing firmly as you form the ball. Place the dough balls onto lined baking sheets. Bake at 350°F for 8-10 minutes, until the edges are set and the centers of the cookies are still slightly underdone. Place baking sheets on a rack to cool.