Preheat the Oven:Preheat your oven to 350°F (175°C).
Mix Ingredients:In a medium-sized bowl, combine Bisquick baking mix and sugar. Add the melted butter (or margarine) and mix until a dough forms. If desired, stir in vanilla extract, lemon/orange zest, and any optional add-ins like nuts or chocolate chips.
Prepare the Baking Sheet:Grease a baking sheet or line it with parchment paper to prevent sticking and ensure even baking.
Shape the Dough:Using a cookie scoop or tablespoon, portion the dough into small rounds and place them on the baking sheet. Flatten each ball slightly with your palm or a fork.
Bake:Bake for 10-12 minutes or until the edges of the shortbread are light golden brown. Keep an eye on them to avoid over-baking.
Cool:Let the shortbread cool on the baking sheet for 5 minutes before transferring them to a wire rack to cool completely.