Soak dates and cashew in lukewarm water overnight (or for at least a few hours) to soften (soak separately, in two bowls).
Rinse te dates and put in a blender along with melted coconut oil, almond meal and hazelnut meal and blend into a uniform and compact mixture.
Roll out the crust between two layers of baking paper and place in a baking pan measuring 25 cm x 21 cm.
Squeeze the lemons and mix lemon juice with water.
Rinse the presoaked cashews and put them in a blender along with melted coconut oil, lemon peel and agave syrup, lemon juice and water.
Blend into a smooth cream, spread it evenly on the crust and place in the fridge for a few hours or overnight to harden.
Cut into 12 pieces and decorate with lemon slices if desired.
Store the slices in the refrigerator.