Preheat the oven to 160°C. Make the base by crushing gluten free biscuits with a rolling pin in a large bowl to form crumbs (Alternatively, blitz them in a food processor). Stir in the melted dairy free butter and press into the base and up the sides of a greased 9” fluted flan tin. Bake in the oven for 15 minutes while you make the filling.
Beat the egg yolks with an electric whisk for a couple of minutes and then add the sweetened condensed coconut milk, lime juice and lime zest and mix again for a minute until combined
Pour the lime mixture into the partially baked crust and bake for another 15 minutes. Remove from the oven (the filling will still be wobbly) and place in the fridge to set for atleast 4 hours, or ideally overnight.
Before serving whisk the dairy free double cream to stiff peaks, add the icing sugar and whisk again until fully incorporated. Spread the cream on top of the key lime pie and decorate with grated lime zest. Store in the fridge for up to 2 days.