Preheat oven at 350°. Grease your cast-iron skillet and set aside.
In a medium mixing bowl, whisk together the cake mix and flour. Set aside.
Add the butter to a large mixing bowl and cream until light and fluffy.
Add both eggs and beat until blended.
Add half of the dry ingredients to the wet ingredients and mix well. Add the rest of the dry ingredients and stir until well incorporated.
Fold in the white chocolate chips.
Transfer the batter to the greased skillet and bake for 12 to 14 minutes or an inserted toothpick comes out clean.
Cool on a wire rack for 10 minutes before serving with ice cream or whipped cream and chocolate topping.