The entire pie has only three tablespoons of sugar, so most of the sweetness comes from the fruit. You could of course use any ripe fruit—strawberries and peaches would both be good.
We've made many frozen pies using Cool Whip as the base. It freezes well and stays relatively creamy even when it's solid. For this pie, we whipped our own cream and used less (the bulk of the filling is nectarines and greek yogurt), so the finished product is a bit icier than some other pies. That didn't really bother us, but if you'd like to experiment, try using less yogurt, more whipped cream—or else use Cool Whip. You can also adjust the sugar (or use vanilla yogurt) if you'd like it sweeter.
We found that letting the pie sit out for about 20 minutes allowed it to soften and smooth out a bit.
4 ripe nectarines, peeled and chopped
3 tablespoons sugar, divided
1 cup heavy cream
3/4 cup plain yogurt
prepared graham cracker or shortbread pie crust
Combine the nectarines and 1 tablespoon of the sugar in a bowl. Stir and allow to macerate for about 30 minutes, then mash slightly with a fork or potato masher.
Meanwhile, whip the cream in a standing mixer (or with a handheld mixer) for about a minute, adding the remaining 2 tablespoons of sugar halfway through, until it thickens to form soft peaks.
Add the yogurt to the bowl with the nectarines and stir to combine. Fold in almost all of the whipped cream, reserving about 1/2 cup to use as topping on the finished pie. Taste and add more sugar, if you'd like. Pour the filling into the pie crust, cover, and freeze for several hours until firm.
Related: DIY Graham Cracker Pie Crust
(Images: Elizabeth Passarella)