For strawberry sauce, set aside 350g/12oz of the strawberries and 60g/2¼oz of the sugar.
In a heavy saucepan, combine the remaining strawberries, 125ml/4fl oz water, 115g/4oz of the sugar, the orange juice, star anise and Grand Marnier.
Bring to a boil over medium heat, stirring occasionally to prevent scorching. Reduce the heat and simmer for 10 minutes.
Remove the strawberries from the heat and cover with cling film. Set aside to infuse for 10 minutes.
Remove the star anise and pour the strawberry mixture into a blender, and blend to a fine purée.
Strain the sauce through a fine sieve and reserve in a pan ready to use, or refrigerate if not using right away.
Preheat the oven to 210C/425F/Gas 7.
For the kaiserschmarrn, generously butter two ovenproof dishes 22cm/8½ in diameter. Dust each pan with sugar and tap out any excess.
In a medium bowl with a hand mixer, beat the egg yolks with 25g/1oz of the caster sugar until mixture is light and lemony yellow.
Beat in the fromage blanc and mix until well combined.
Beat in the crème fraîche and rum, then beat in the flour. Stir through the raisins.
In another bowl and using an electric whisk or stand mixer, whisk the egg whites on medium-low speed until they foam, then add the cream of tartar.
Turn the speed up to medium and continue to beat while slowly pouring in the remaining 150g/5½oz sugar. Whisk until stiff peaks form when the whisk is removed.
Whisk half the egg whites into the crème fraiche mixture, then gently fold in the remaining egg whites.
Divide the mixture equally between the two sugared pans.
Bake the kaiserschmarrn in the middle of the oven for 15 minutes. Turn the pans if browning unevenly and bake for another 5-8 minutes, until puffed and brown. The center should be set and slightly firm.
Meanwhile, in a large saucepan, bring the strawberry sauce to a boil over high heat. Add the reserved 60g/2¼oz sugar and stir until the sugar has dissolved. Cook the sauce over a high heat for a minute.
Add the reserved 350g/12oz cut strawberries, and stir through the sauce to coat. To serve, divide the strawberry sauce among four serving plates.
Using a serving spoon divide each one into two portions and spoon on top of the strawberry sauce. Dust with icing sugar and serve immediately.