Place the softened butter and sugar into the bowl of your stand mixer with flat beater attachment, beat until it is light and fluffy. Add the yolk and mix again.Use a rubber spatula to scrape the sides  of the bowl while mixing.

Add the flour and salt, mix for 30 seconds or until crumbs form. It is important not to over mix the dough!

Transfer the dough on a baking tray lined with parchment paper, cover with plastic and freeze for at least 30 minutes.

Preheat your oven to 350° F| 180°C.

Bake for 17-20 minutes. The baked pâte sablée should be crispy and golden brown. Allow to cool down completely.

Grind into crumbs in a food processor. Transfer to a medium bowl.

Add the pistachio flour, almond flour, chopped pistachio , coconut oil and butter, and mix to combine.

Press into bottom and sides of a 8-inch(20 cm) cheesecake pan with 3-inch (7 cm) sides and freeze for at least 30 minutes.

Preheat your oven to 300° F| 150°C.

In a mixer bowl fitted with paddle attachment, beat cream cheese with sugar on medium-high speed until very smooth, about 2 minutes.

Add eggs, one at a time, beating after each addition. Stir in pistachio paste, heavy cream and chopped pistachios. 

Remove the cheesecake base from the freezer. Pour over the frozen crust, smoothing out to sides of the pan. 

Bake in the preheated oven over water bath until top is light brown and center has a slight jiggle to it, about 60-90 minutes. Allow to cool in a pan on a wire rack for 2 hours. 

Once it is baked, cover with plastic wrap and refrigerate for at least 6 hours before decorating. 

Combine well-chilled heavy cream and cream cheese in a bowl.

Add the powdered sugar, pistachio paste and beat on medium until smooth. Use your stand mixer or a hand mixer.

Pipe rosettes around the cake. Sprinkle with chopped pistachios.