Better Yellow Cupcakes From a Box

1 box (18.25 oz.) yellow cake mix
1 1/4 c cake flour
1 C sugar
4 eggs
1 C evaporated milk
1 c sour cream
3/4 C vegetable oil
1 T vanilla
Heat oven to 350 degree F. Mix cake mix, flour and sugar in a large bowl with and electric mixer on low speed, about 10 seconds. Add eggs, milk, sour cream, oil and vanilla; beat on low speed just to combine, about 30 seconds. Increase speed to medium high;beat until light and fluffy, about 2 minutes. Place in greased muffin tins and bake for 20-25 minutes. Coll in pans for 5 minutes and remove to cool on wire racks. Frost as desired.