I just had cake batter ice cream at a little shop in Estes Park, CO on vacation and became obsessed! The guy at the counter said all they did was mix a box of regular Duncan Hines yellow cake mix with plain "sweet cream" ice cream which is the base for all the marble-slab flavors. I have an ice ceream maker so my plan is to make regular either sweet cream or vanilla ice cream, mix in half a box of cake mix (because their batches are much larger than the single gallon I make) and see how it tastes. I plan to do it today or tomorrow, so I'll let you know how it goes!