Preheat oven to 375
Whisk together the cornstarch and salt in a small bowl.
Add in 4 eggs, cream, maple syrup, maple extract, and extracts.
Whisk to combine.
Add the buttermilk and whisk to combine.
Slowly pour the filling into the pie crust.
Place the pie onto your oven’s middle rack and bake it for 40 minutes.
Remove the pie from the oven, and place it on a rack to cool.
Mix together the sour cream, maple extract, sugar & vanilla.
Pour over the pie and bake for 4 minutes at 375 degrees.
Cover & chill overnight in the fridge.