1 cup butter softened ▢1 cup vegetable oil ▢1 cup sugar ▢1 cup powdered sugar ▢2 eggs ▢1 tsp vanilla extract ▢4 1/2 cups all purpose flour ▢1 tsp baking soda ▢3/4 tsp cream of tartar ▢1/2 tsp salt
Preheating a cookie sheet with oil and a 375°F/190°C oven
Combine the butter, oil, white sugar, and confectioners' sugar in a large basin. Combine the ingredients until homogeneous. Gradually incorporate the eggs while beating in between each individual egg. Integrate the vanilla.
Whisk together the flour, baking soda, cream of tartar, and salt in a separate basin. Mix the flour into the sugar mixture until only barely combined.
Using teaspoonfuls, drop the dough onto the greased cookie tray. Bake until the bottoms are faintly browned, 8 to 10 minutes. After removing the cookies from the oven, transfer them to a wire rack to chill.
Drizzle the cookies with glaze, if desired.