Ingredients:

  • 8 oz (225 g) Digestive Biscuits or Graham Crackers, finely crushed
  • 1/2 cup (60 g) shelled pistachios, finely ground
  • 6 Tbsp (85 g) unsalted butter, melted
  • 1 Tbsp (15 g) granulated sugar
  • 1/4 tsp (1 g) sea salt
  • 8 oz (225 g) high-quality white chocolate, chopped or chips
  • 2 cups (475 ml) heavy cream (35% Fat), very cold
  • 1 cup (225 g) whole milk mascarpone cheese, very cold
  • 1/2 cup (60 g) powdered sugar, sifted
  • Zest of 2 large lemons
  • 1/4 cup (60 ml) fresh lemon juice
  • 1 tsp (5 ml) vanilla extract

Instructions:

  1. Prep the Components: Crush the biscuits and finely grind the shelled pistachios in a food processor until they resemble coarse sand.
  2. Mix the Base: Transfer the biscuit and pistachio mix to a medium bowl. Pour in the melted butter, granulated sugar, and salt. Stir until the mixture is evenly damp.
  3. Form the Crust: Press the mixture firmly and evenly into the bottom and up the sides of the 9-inch tart tin. Use the base of a measuring cup or glass to ensure compaction.
  4. Chill and Set: Refrigerate the crust for a minimum of 30 minutes to firm up.
  5. Melt the Chocolate: Gently melt the white chocolate using a double boiler or in 30-second bursts in the microwave, stirring until completely smooth.
  6. Cool Down: Allow the melted chocolate to cool to just slightly warm room temperature. (This step is crucial to prevent melting the mascarpone).
  7. Whip the Cream: In a chilled mixing bowl, whip the heavy cream, powdered sugar, and vanilla extract until stiff peaks form. Be careful not to over-whip.
  8. Prepare the Mascarpone Base: In a separate large bowl, gently whisk the cold mascarpone cheese to loosen it slightly. Add the lemon zest and lemon juice. Mix briefly just until combined.
  9. Combine the Chocolate: Slowly pour the slightly cooled melted white chocolate into the mascarpone mixture, mixing just until streaks disappear.
  10. Fold in the Cream: Gently fold about one-third of the whipped cream into the mascarpone mixture to lighten it. Then, carefully fold in the remaining whipped cream in two additions, using a figure-eight motion until just combined. Do not overmix.
  11. Fill the Crust: Spoon the creamy filling into the chilled tart crust, spreading it evenly with the back of a spoon or offset spatula.
  12. Long Chill: Cover the tart loosely with cling film and refrigerate for at least 4 hours, or preferably overnight, until the filling is fully set and firm to the touch.
  13. Serve: Remove the tart from the fridge 15 minutes before serving. Carefully remove the outer ring of the tart tin. Garnish as desired before slicing.