This one is just too easy. But it tastes good, so I am not complaining.
First make a batch of Custard. Yep. The same recipe for frozen custard makes the basis for a great pie. Just let it cool somewhat before using in the pie. Anything down to room temperature is fine. If you can eat it warm off a spoon without having to blow on it too much, your temperature is fine.
Then get a pie pan lined with a Graham Cracker Crust. Yes, you may buy one, but the crust is easy and quick to make and you can use one of the cookie variations for more fun.
Pour enough custard to cover the bottom of the pie.
Decide what kind of custard pie you want. If banana, slice two bananas onto the custard on the bottom of the pie shell. If coconut, sprinkle about a cup of coconut on the bottom. If both, put in enough (just look at it...this is pie...how bad can it turn out?). Pour the rest of the custard on top of the "filling". Refrigerate. It's better after a day, much better after two days, then you'd best get down to eating it.
If you use really ripe bananas they will taste good quicker than only slightly ripe bananas, but they will turn brown sooner. But my pies don't generally last much more than a day, so speed is less of a factor than flavor. I like ripe bananas.