Keto Sugar Free Double Chocolate Custard Pie

Mix the dry ingredients; melt the butter and combine; transfer to a lined 20.5-22cm/8-9" silicone mould.
Spread, press and smooth with the back of a spoon to obtain a thin, lightly compacted and even base layer; set aside on an oven rack.
Pre-heat oven to 170°C static.
Separate the eggs, using two mixing bowls: large for the egg whites and medium for the yolks.
Using an electric whisk, beat the yolks with erythritol and stevia until pale and smooth; incorporate whipping cream and crème fraîche, whipping a little longer; add sifted lupin flour and cocoa powder and whip again until well combined.
Whip the egg whites to stiff peaks; detach the balloon whisk and manually (and very gently) fold in 1/2 of the chocolate mixture; add the remaining chocolate mixture and fold once again, ensuring air bubbles remain trapped.
Pour the filling over the pie base, slide the tray carefully into the middle of the oven and bake for 45 mins.
Turn off the heat and leave the pie in the oven, door closed, for a further 15 minutes, then remove it and let it cool before transferring it to the fridge in its mould.
Chill the pie until set (best overnight), un-mould and serve.