I noticed it at RPR too when we were there but did not try it. It was only offered one night during the week and it sounded like it might have been fun.
It is offered at The Kitchen, which is a restaurant on the first floor of the HRH (which is very kid-friendly, though a bit overpriced). They offer different experiences on different days, so you need to check with them (or the hotel) on what is offered when you get there.
Yes, we went to the Kitchen one night for dinner and both kids put on aprons and made their own pizzas. They bring the kids right up next to the kitchen and let them assemble the pizza. They had a good time.