Preheat the oven to 375F (190C). Lightly grease a cookie sheet
. Mix together sugar, butter, confectioner's sugar, oil and butter in a large bowl until smooth. Beat in the eggs, one at a time, and then the vanilla. In a separate bowl, combine the flour, cream of tartar and baking soda. Stir flour mixture into the sugar mixture until combined. Drop by the teaspoonful onto the cookie sheet. Bake
for 8 to 10 minutes or until bottoms are lightly browned. Remove from sheet and cool on a wire rack.