Line bottom rack with aluminum foil to catch drippings. Preheat oven to 350. Wash and dry potatoes. Poke a few holes in skin with a fork and place on middle rack. Roast until you can smell the potatoes (approx 90 min) Poke a chopstick in middle to check for doneness.
Remove from oven and let cool. Remove skins. During this time, preheat oven to 350 and take pie crust out of fridge to warm up. Crust will crack if too cold. Mash sweet potatoes with remaining filling ingredients, reserving 1-egg for egg wash.
Roll out pie crust and place over 9-in tin. Spoon in filling. Roll edges in, then crimp between index finger and thumb along outer edge while using opposite index finger to push inner edge between fingers. Use extra dough to cut shapes and decorate.
Brush dough with egg wash and bake at 350 for approx 1hr. Allow pie to set and serve warm or put in refrigerator and serve later chilled
Whipped cream
Chill heavy whipping cream over night. Chill metal mixing bowl and beaters in freezer at least 1hr before
Pour cream into bowl and whisk in electric mixer on med low, add sugar and vanilla extract.
Slice open vanilla pod and scrape seeds with a spoon into mixer. Increase speed to high until peaks formed.
Adjust sugar for sweetness and whip until desired thickness reached
Note: To make coconut whip cream substitute canned coconut milk, including solids. Use sugar only, no vanilla extract or vanilla bean