In the bowl of a stand mixer (or using a hand mixer), beat sugar, powdered sugar and butter until light and fluffy.
Add oil, vanilla and eggs and mix until incorporated.
Stir in flour, baking soda, cream of tarter and salt. Mix until blended well.
Add white chocolate chips and dried cranberries and mix until just blended.
Cover dough with plastic wrap and chill overnight. (If you cannot chill dough overnight, chill at least 2 hours.)
Preheat oven to 375 degrees F.
Shape dough into 1-inch balls and place 2 inches apart on ungreased cookie sheets.
Bake cookies for 5-8 minutes or until set but not brown. Immediately remove cookies from cookie sheets.
Cool cookies on wire rack.
Recipe yields 9-10 dozen cookies. You can cut the recipe in half if you want less cookies.