How early can the assembly and storage take place?

The baked pie crust filled with caramel and pumpkin ganache should be in the fridge for a minimum of 8 hours before serving. I'd say it should be good for about a day, any longer than that and the crust will likely start to get a little soggy but will still be tasty. I would wait to layer on the whipped cream and streusel until right before serving, though. The whipped cream will deflate and the streusel will lose its crunch. Enjoy!

-Ella from the F52 test kitchen