Part melt the pistachio ice cream (if you need to place in to a food processor and blitz until it’s malleable). Place into a 20cm x 20cm square tin, spreading out to the sides and place back into the freezer for at least 3 hours, or overnight.
When ready to make the baklava, place the nuts, cinnamon and sugar into a food processor and blitz until fine.
Unroll your filo sheets, keeping a damp cloth handy to place over filo sheets while making the baklava to prevent the filo drying out. Cut the filo into 10cm x 10cm squares.
Preheat the oven to 180°C and grease a flat baking tray with some of the melted butter. Place a filo sheet on a clean work surface. Brush with butter, top with another filo sheet, then brush with the butter.
Repeat the process until 4 layers are formed. Sprinkle the top with the chopped nuts and spread with your fingers.
Top with a further 3 sheets of buttered filo and finally top with a final sprinkling of the chopped nuts.
Bake for 15 minutes or until golden on top.
Mix the honey with the water and orange blossom water.
To assemble, remove the ice-cream from the freezer and cut into 10cm x 10cm squares. Remove the baklava squares from the pan. Place each ice cream square on top of one baklava, then top, nut-side up, with another baklava. Finally, pour the syrup over the baklava.
Garnish with extra nibbed pistachios and serve immediately.