Start by removing the filling from the Negresco biscuits and crushing the biscuits into small crumbs (feel free to leave a few larger pieces for texture).
Mix the Butter:
In a mixing bowl, combine the crushed biscuits with the margarine or butter. Blend them until you achieve a homogeneous mixture.
Shape the Pie:
In a removable pie pan, press the biscuit mixture firmly to form the pie’s base. Ensure to leave some flaps on the sides for a beautiful finish.
Bake the Base:
Preheat your oven to a low setting and place the pie base in for about 5 minutes just to set it.
Create the Filling:
In a blender, combine the juice of the lemon, condensed milk, and cream. Blend until smooth and combined.
Fill the Pie:
Pour the lemon filling into the baked biscuit base and return it to the oven for another 5 minutes.
Cool and Chill:
Let the pie cool at room temperature, then place it in the fridge for a couple of hours to firmly set.
Serve:
Once chilled, you're ready to slice! Decorate with whipped cream, lemon zest, or additional cookie pieces if desired.