In the one bowl, combine the lemon cake mix, baking powder, and flour. Whisk until the dry ingredients are combined.
In the other bowl add the vegetable oil, eggs, and milk. If you have a lemon you can add some lemon zest to this as well. Whisk these ingredients until well combined.
Next pour the wet ingredients into the dry ingredients and continue to stir until it is all mixed together. Fold in the white chocolate chips and then spoon the mixture into your prepared lined muffin (18) or cupcake pan (24).
Then bake at 350 degrees F for about 18 minutes or until lightly browned and center is cooked. Let cool and enjoy!