Preheat the oven to 325°F.

For the tart shell, combine the butter, icing sugar and salt in the bowl of a stand mixer fitted with the paddle attachment. Cream until light and fluffy. Add the egg and beat to combine, until fluffy.

Sift together the all-purpose flour, almond flour and cocoa powder. Add to the butter mixture, beating on medium-low speed until it just comes together. Remove the dough from the bowl, flatten into a square and wrap with plastic wrap. Chill in the fridge for 20 minutes.

While the dough is resting, make the passionfruit filling. Combine the eggs, cream, passionfruit purée and sugar in a bowl and blend with an immersion blender. Strain the mixture into a clean bowl and set aside.

Remove the dough from the fridge and lightly flour your work surface. Roll out the dough to 12 inches in diameter and about 1/8 inch thick.

Spray a tart pan with nonstick spray, then line it with the dough, letting it hang over the sides without stretching it. Trim off any excess.

Line the bottom of the tart shell with aluminum foil and fill with baking beans. Bake in the preheated oven for 10 minutes. Remove the baking beans and bake for another 5 minutes, until light golden brown. Remove from the oven and let cool completely.

Remove from the oven and place in the fridge to cool. Once the tart is cool, remove the pan.