Preheat oven to 180℃ (160℃ fan forced). Grease and line a 22cm round springform pan with baking paper. Sift the plain flour with the baking powder into a bowl and set aside.
Cream the butter and sugar in a large mixing bowl or the bowl of your stand mixer until light and fluffy (about 5-6 minutes). Add the eggs, one at a time, beating well between each addition. Add vanilla and beat to combine.
Add ⅓ of the flour mixture and beat on low speed until combined, then beat in ⅓ of the milk. Repeat alternately with flour and milk until mixture is combined.
Add the coconut and using a spatula, fold through until combined.
Spoon mixture into prepared pan and bake in the oven for 50-55 minutes or until cooked when tested with a skewer. Remove and allow to cool in pan over a wire rack for 20 minutes.
Place a tray, which is larger than the springform pan under the cake tin (this will catch any "excess" syrup leaking out). Using a skewere, poke deep holes all over the cake. Starting from the middle of the cake, slowly pour over the Lemon Syrup to cover and allow to cool completely in pan. The syrup will slowly absorb into the cake on cooling.
To serve, garnish with extra desiccated or toasted coconut and the reserved lemon zest from the Lemon Syrup. Cut into slices to serve. Serve with ice cream, whipped cream or on its own.