- 1 cup butter
- 1 cup vegetable oil
- 1 cup white sugar
- 1 cup packed brown sugar
- 2 eggs
- 1 teaspoon vanilla extract
- 4 1/2 cups all-purpose flour
- 2 teaspoons baking soda
- 4 teaspoons cream of tartar
- 1 teaspoon salt
- 2 cups semisweet chocolate chips
- 1 cup chopped walnuts (optional)
- Preheat the oven to 350 degrees F (175 degrees C).
- In a large bowl, cream together the butter, oil, brown sugar, and white sugar until smooth. Beat in the eggs and vanilla. Combine the flour, baking soda, cream of tartar, and salt; stir into the creamed mixture. Mix in the chocolate chips and walnuts. Drop dough by rounded teaspoons onto ungreased cookie sheets.
- Bake for 12 to 15 minutes in the preheated oven, or until light brown. Allow cookies to cool on the baking sheets for a couple of minutes before transferring to wire racks to cool completely.