Preheat the oven to 200°C (180°C fan forced). Grease a 7 cm deep, 9 x 19 cm loaf pan and line with baking paper.

Coarsely chop half the pistachios and walnuts for topping, and finely chop the remaining half for layering.

Brush thawed puff pastry sheets with melted butter, sprinkle with ground cinnamon and finely chopped nuts, then drizzle with more butter. Bake for 8 minutes until golden.

Remove from oven and pierce with a fork, then press flat with a baking tray. Return to oven for another 8 minutes and let cool completely on a wire rack.

In a saucepan, combine 375 ml pouring cream, 1 teaspoon vanilla extract, 170 g caster sugar, and 250 ml milk. Stir and bring to a simmer.

Whisk together 35 g cornflour, 6 egg yolks, and remaining milk until smooth.

Temper the yolks by whisking a ladle of hot cream mixture into them, then pour back into the saucepan. Cook on medium-low heat, whisking for about 5 minutes until thickened.

Cut baked pastry sheets into four rectangles. Layer in a loaf pan with custard, alternating layers until finished with pastry on top. Press gently.

Cover and refrigerate for at least 8 hours or overnight.

In a saucepan, combine remaining caster sugar, 60 ml lemon juice, 2 tbsp honey, cloves, cinnamon stick, and water to cover. Heat until sugar dissolves, then simmer for 3 minutes. Strain and stir in rosewater, let cool.

Lift chilled slice from the pan, sprinkle with coarsely chopped pistachios and walnuts, drizzle with syrup, slice, and serve.