White Chocolate Fudge Cake

Ingredients
14 oz butter, chopped
17 oz white chocolate, chopped
2 cups caster sugar
2 teaspoons vanilla extract
4 eggs, lightly beaten
2 cups plain flour, sifted
2 cups self-raising flour, sifted
fresh roses, to decorate

White chocolate ganache
21 oz white chocolate, chopped
3/4 cup thickened cream
Directions:
Preheat oven to 300 F. Grease and line an 3 inch deep, 9 inch (base) square cake pan.
Combine butter, chocolate and 400ml water in a large heatproof, microwave-safe bowl. Microwave, uncovered, on HIGH (100%) for 3 to 4 minutes, stirring every minute with a metal spoon, or until smooth.
Add caster sugar and vanilla to chocolate mixture. Stir to combine. Add egg. Mix well. Sift flours together over chocolate mixture. Stir until well combined.
Pour mixture into prepared pan. Bake for 1 hour 50 minutes to 2 hours or until a skewer inserted into the centre has moist crumbs clinging. Allow to cool completely in pan. Carefully turn cake out. Wrap in plastic wrap, then in foil. Store in an airtight container at room temperature for 5 to 14 days.
Make white chocolate ganache:
One day before serving, combine chocolate and cream in a heatproof, microwave-safe bowl. Microwave, uncovered, on MEDIUM (50%) for 2 to 3 minutes, stirring every minute with a metal spoon, or until melted and smooth. Refrigerate for 1 hour, stirring occasionally with a metal spoon, or until thickened to a spreadable consistency.
Using a serrated knife, cut cake in half. Place base on serving platter. Spread one-third of ganache over base. Sandwich together with cake top. Spread remaining ganache over top and sides of cake. Set aside for 24 hours to set. Decorate with fresh roses. To serve, cut cake with a warm knife to prevent ganache from cracking.