Fry saffron in a dry saucepan briefly, add milk and vanilla, then heat to scalding.
Whisk egg yolks, sugar, and flours together, then whisk in scalded milk and heat until thickened.
Dissolve sugar in 50ml water, add pomegranate, Grand Marnier, and rosewater, then reduce to a syrup.
Add raspberries to the syrup and allow the mixture to cool.
Pipe pastry cream and pistachios into courgette flowers and twist ends to seal.
Whisk batter dry ingredients with egg and sparkling water.
Heat vegetable oil in a heavy saucepan for deep-frying.
Dip flowers in batter, deep-fry until golden, and roll in cinnamon sugar before serving with sauce.