Preheat the oven to 350°F. Lightly grease a 9-inch tart pan with a removable bottom and set aside.
To a large bowl add oat flour, oats, maple syrup, baking powder, salt, and coconut oil and mix until combined.
Pour half of oat mixture into tart pan and press into all the sides until you get a nice and sturdy crust. Pour the rest of the mixture and press into the bottom. Really pack it down. Bake in oven for 20-25 minutes or until golden.
While the shell bakes, prepare the filling. On medium heat, whisk coconut cream and coconut oil until just hot to the touch. You don't want to boil it. Pour over chocolate chunks and whisk until fully melted. Add vanilla extract and stir in. Set aside.
Once tart is fully baked and has cooled for about 5 minutes, pour filling over baked tart until full and set in fridge for at least 2 hours.
To make hazelnut cream, combine the coconut cream (you only want the solid stuff on top - discard any liquid from the can), hazelnut butter and maple syrup in a stand mixer. Whisk until fluffy, about 5 minutes.
When your tart has set, remove from the fridge to decorate. Using a piping bag pipe dollops of the hazelnut cream however you'd like. Top with your choice of berries, chocolate chunks, and roasted hazelnuts. You can see the video below for how we decorated ours.
To store keep in the fridge.
*You want to chill this can of coconut cream in the fridge overnight or at least 8 hours before using it. All you want is the thicker cream on top, not the liquid below.