Prep sweet potato: If starting with raw sweet potatoes, you'll need around 650g. Roast them on a lined baking sheet for 40-45 minutes at 425°F (220°C) until soft. Cool to room temperature and puree or mash with a fork. You'll need 400g of cooked sweet potato puree in total.

Prepare: Lightly grease a 9-inch pie tin with a small amount of oil or vegan butter. Line the base with a round of parchment paper, cutting small slits around the edges to help it sit neatly into the tin without creasing.

Crust: Add the cookies to a large ziplock bag and crush them using a rolling pin until finely ground. Transfer the crumbs to a mixing bowl, pour over the melted vegan butter, and mix with a spatula until the texture resembles wet sand. Alternatively, you can blend the cookies and butter in a food processor until evenly combined.

Press the crust mixture into the base of the prepared pan. Use a spoon or the bottom of a flat glass to smooth and firmly compact it into an even layer. Place the crust in the freezer to set while you prepare the filling.

Filling: Add all of the filling ingredients to a food processor, except for the maple syrup (if using). Blend on high until completely smooth and creamy. Give it a taste and, if you'd like it sweeter, blend in the maple syrup.

Spoon the filling into the prepared crust and use an offset spatula or the back of a spoon to smooth out the surface. Transfer the pie to the fridge and chill for at least 2 hours, or until set.

Toppings: In a mixing bowl, whisk together the chilled vegan whipping cream and cocoa powder until light and fluffy. Spoon the whipped cream on top, then finish with a generous sprinkle of chocolate shavings.