Preheat oven to 160°C. Grease and line base and sides of a round 23-25cm springform cake tin with baking paper.
In a large mixing bowl, use an electric beater to beat butter, sugar and vanilla until thick and pale.
Beat in eggs, one at a time, making sure each egg is well incorporated before adding the next, until mixture is fluffy and creamy.
Stir in warmed milk, coconut, lime zest, sifted flour and baking powder and a pinch of salt. Use a large metal spoon to fold together until you have a uniform batter. Spoon into tin and bake for about 1 hour or until a skewer inserted into the middle comes out clean. Allow to cool a little then transfer from tin to wire rack. When completely cool, use a large knife to carefully cut cake in half horizontally.
Gently melt chocolate in a large glass bowl set over a small pot half-full of gently simmering water; or use the microwave or a double boiler (see tips below). Stir gently then leave to cool for about 10 minutes. In a separate bowl, whip cream until soft peaks form. Fold a few tablespoons of whipped cream into cooled chocolate, then fold in rest of cream (make sure chocolate is cool; if too warm it will melt the cream.) Gently fold half the raspberries through the cream.
Spread one-third to half of the white chocolate cream over one half of the cake. Place other half on top and spread with remaining cream. Garnish with raspberries, toasted coconut, white chocolate and lime zest.