Prepare your shells by separating your egg whites and yolks. Firstly whisk the egg whites with a pinch of salt and 1 tsp of lemon juice to stiff peaks by adding half of the caster sugar in two times. Once you prepared your glossy meringue, set it aside.

Whisk your egg yolks with the vanilla, the other half of caster sugar and grated lemon zest, until pale. Add your meringue one serving spoon at a time and fold from the bottom trying to keep as much air as possible.

Sift your flour and add to the egg mixture in two halves, and incorporate with a spatula always being mindful not to mix the batter. Transfer in a piping bag and make some disks of about 9 cm on a baking tray covered in parchment paper. You can use a cutter or chef ring to draw the outline.
Bake for 5 minutes in a preheated oven at 200 C. Once the shells are cooked, move to a cooling rack to cool down, these should remain soft.

In the meantime, prepare your mousse by whisking all ingredients into a bowl. The quantities are enough to fill 9 cannoli, however, if some has left, just place in small cups for a light dessert.
Once the ingredients have reached a soft but firm consistency, place them in a piping bag with a star nozzle.