White Chocolate, Pistachio and Cardamon Wedding Cake with Rosewater Butter- cream Frosting

Ingredients for 1 layer of 12 inch round cake. (I used 3 layers for this cake.)

300 g white chocolate (at least 26% cocoa butter)
250g unsalted butter, chopped into cubes.
8 tbs cream
250 g caster sugar
6 eggs, separated
200 g plain flour
100 g pistachios, ground in food processor until fine. (Grind nuts with a little of the flour so they do not turn to paste)
50 g pistachio paste (I used the dark green Sevaromme brand according to the cake decorating shop that had decanted it into little containers)
1 1/2 tsp ground cardamon

Method
Grease and line cake tin.
Pre-heat oven to 160°C non fan forced.
Heat cream in microwave in a microwave proof glass bowl until just boiling.
Melt chocolate in hot cream.
Stir in butter to melt.
Stir in pistachio paste. It should be a smooth olive green mixture.
Set aside.

Whisk egg yolks and sugar until pale and fluffy.
Stir in room temp chocolate mixture.
Fold in ground pistachios.
Mix in plain flour and cardamon.
Whisk egg whites until stiff peaks. Fold into chocolate and pistachio batter.
Pour into greased and lined 12 inch round cake tin.
Bake in oven for 45-60 mins or until golden and skewer comes out clean.
Cool cake in tin for 20 or so mins and then on rack completely before frosting.

Rosewater Butter cream:

Whip 250 g unsalted softened butter with 50g “cream shortening”  until pale and creamy. Whip in 300g cake making “soft fondant” and 1 tsp ( or to taste) rosewater until pale and creamy.