Half a pan of brownies, made family style brownie sundae by baking in a deep dish, then letting cool a bit, scoop ice cream and sauce / toppings and all dig in. I LOVE doing this. Or you can set out some toppings, then make a brownie batch and bake them in ramikins, and give everyone to top themselves. They freeze good this way, just pop them out, wrap, then reheat a little for next time.
Fondue is good because you can just make a little bit. Cakes of any kind can be made and half of it frozen by baking a 2 layer, then wrapping/freezing one. Make it torte style by slicing, fill with jam/pudding/choc, and drizzle with chocolate ganache.
Baked apples/pears with ice cream are good, all you have to do is core and half cut side up, sprinkle with nuts/cinnamon/brown sugar or whatever you like and bake, then serve with a little ice cream/whip cream.
I've made homemade ice cream without churning by whipping up heavy cream, sugar and a little milk, then just freeze it in a container. It's whipped up so it doesn't freeze rock hard and you can make a little bit
Puddings always good for something simple and it's quick easy and you can make a small batch.