For the almond dacquoise, preheat the oven to 200c. Process the almonds and icing sugar in a food processor until finely ground. Alternatively mix and shift through mesh. Set aside. In a separate bowl, whisk the egg whites with an electric mixer until soft peaks (around 3 to 4 minutes) then add the caster sugar and whisk until stiff peaks form (around 1 to 2 minutes). Gently fold through almond mixture, spread on a 30 cm by 40 cm oven tray lined with baking paper and bake around 10 to 15 minutes until golden. Keep an eye on this part as it can easily burn. Set aside to cool on a tray, then cut in half, lengthways.
2
Arrange the watermelon slices in a single layer on a wire rack. Sprinkle with 20 ml rosewater then scatter 2 tbsp sugar. Stand to macerate around 30 minutes then pat dry with absorbent paper.
3
Meanwhile, for the rosescented cream, whisk the 300 ml cream with the 30 grams sugar in an electric mixer until soft peaks form, gradually add the rosewater and whisk until stiff peaks form (do not overwhisk).
4
Spread 1/3 of the rose cream evenly over the half dacquoise, scatter half the almond meal (20 grams), then layer the watermelon, the remaining almond meal (20 grams) then spread over half the remaining cream. Top with the remaining dacquoise, spread over the remaining cream and refrigerate 1 to 2 hours until firm.
5
Combine the strawberries, remaining rosewater and remaining sugar in a bowl, toss to combine and set aside to macerate (around 15 minutes). Carefully arrange on top of the cake, gently pushing into the cream. Trim the edges of the cake, scatter over the grapes, pistachios and serve. (Optional – 1 tbsp dried rose petals to spread over the cake as well.