1 cup (2 sticks) butter
1/2 cup sugar
2/3 cup packed brown sugar
2 large eggs
1 tsp. vanilla
2 cups plus 4 tbsp. flour
1 tsp. salt
1 tsp. baking soda
2 tsp. cream of tartar
2 cups semi-sweet chocolate chips
1 cup coarsely chopped nuts

Preheat oven to 350°F.

Beat butter and sugars in a large mixing bowl until light and fluffy. Add the eggs and vanilla. Mix well.

Mix the flour, salt, baking soda and cream of tartar in another bowl. Add the dry ingredients to the batter and mix until well blended. Stir in the chocolate chips and walnuts. Spread dough into a 15 1/2 inch round pizza pan. Bake at 350°F for 20 minutes. When cool, may be decorated.