I'm making an icing this morning and just realized I have only 80 grams of butter when I need 100. The recipe also calls for 250 grams of cream cheese, which I have extra of. Could I just add in 20 extra grams of cream cheese to fill it out? Or could I use some vegetable shortening or my smart Blend butter (ie fake butter) to replace the missing 20 grams? Or should I just scale the recipe down? I already know I won't use all of it.