White Chocolate Whipped Cream: Heat the cream in a saucepan over medium-low heat until it begins to steam. Remove from heat then stir in the white chocolate until fully melted. Place mixture into the fridge to cool completely, about 2 hours.
Cake: Preheat the oven to 180 degrees C. Grease and flour two 20cm round cake tins.
Whisk flour, baking powder, bicarbonate of soda and salt together in a bowl; set aside.
Beat butter and sugar in a large bowl with an electric mixer on medium speed until fluffy, about 2 minutes. Beat in egg whites, one at a time, beating well after each. Add flour mixture and buttermilk alternately to mixture, beating well after each addition. Beat coconut milk into cake mixture. Fold in coconut flavouring, vanilla and desiccated coconut. Divide cake mixture evenly into the prepared tins.
Bake in the preheated oven until a knife inserted near the centre comes out clean, about 25 minutes. Cool cakes in tin on a wire rack for 10 minutes, then remove from tin to cool completely on wire rack.
To Assemble: Place one cake layer on a serving plate, upside down. Spread lemon curd evenly over the top; place second cake layer on top.
Whip the white chocolate whipped cream mixture with an electric mixer until stiff peaks form, about 3 minutes. Whip in the vanilla.
Ice the sides and top of cake with white chocolate whipped cream. Garnish with additional coconut. Chill cake in the fridge until ready to serve.