Grease two 20cm sandwich tins with butter, line the base and sides of each tin with baking paper, grease and dust with self-raising flour.
For cake, mix cocoa and boiling water together in a cup and set aside to cool.
Beat butter and sugar in an electric mixer until pale and creamy. Add eggs one at a time, beating well after each addition. Sift flours with bicarb soda and stir into butter mixture. Add milk and vanilla and mix well.
Gradually stir in cocoa mixture until just combined. The batter occasionally curdles at this stage, but will not spoil the finished cake.
Pour into prepared cake tins and bake for 30-35 minutes or until an inserted skewer comes out clean. Allow to stand for five minutes before turning out onto a wire rack to cool.
For chocolate dipped strawberries, dip strawberries halfway into melted chocolate and place on a baking tray to set until ready to decorate.
For filling, whip cream with icing sugar and vanilla in the small bowl of an electric mixer until stiff peaks form.
Take one cooled cake as the base, spread cream thickly on top and freeze for 10-15 minutes, until firm. Place a layer of sliced strawberries onto cream. Spread the top of the second cake with remaining cream and
invert onto first cake layer. This gives you a level top layer.
For chocolate ganache, heat about 3cm of water in a medium saucepan, place chocolate in a metal bowl over simmering water and gently melt the chocolate, stirring occasionally. Remove bowl from heat, add butter and stir through until combined and ganache starts to thicken.
Spread over the cake immediately and decorate with crystallised violets and chocolate dipped strawberries.