Add all the ingredients to a food processor and process until the crust with small crumbs is formed. Scoop the dough into a muffin pan and press it gently with a form. Place the tartlets in a fridge and let it firmed up while making the blueberry layer.
Clean the food processor. Place all the ingredients for the blueberry layer to your clean food processor. Process until very smooth. Scoop the dough on the top of the crust and leave i in a fridge.
Place the the both butters in a heatproof bowl over a boiling water and while stirring constantly, melt it gently.
Pace the cashews in a food processor and pulse a few times untill smooth. Add all the remaining ingredients and proces shortly. Pour the white chocolate over the top of the tartlets and leave it in a fridge or freezer for at least 2 hours.
Decorate with edible plants ad grated dark chocolate. Enjoy!