I got this off the 3fc ww desserts board:
One box cake mix (you can use any brand)
I 12-oz can of diet soda (your choice brand or flavour)
Mix the diet pop with the cake mix and pour into a greased/sprayed baking pan.
Bake according to box directions, but check often.
Top with FF cool whip mixed with 1 small box FF SF pudding mix
1 box of cake mix is 48 points for the box.
1 diet coke is 0 points.
48\12 = 4 points per serving. You can make 24 cupcakes and they are 2 points each. but the piece of cake is 4 points!
These are some variations that people make.
Chocolate cake mix with diet cherry coke. Mix sf cherry jello powder with cool whip for the "icing". Keep refridgerated.
Vanilla/white cake mix with diet orange soda. Mix sf orange jello powder with ff coolwhip for "icing". Keep refrigerated.
Vanilla/white cake mix with diet 7-up or sprite. Once cake is cooled make some small holes in the top of the cake about an inch or two depending on depth of cake. Make some sf lemon jello and let cool at room temperature. When jello has cooled pour liquid into hole in cake. Refrigerate until jello has set. Mix sf jello powder with ff cool whip for icing.
I suppose you could do the same with ther other flavours too.