Combine the flour, sugar, oats and coconut in a bowl. Make a well in the centre.
Place the golden syrup and butter in a saucepan over low heat and allow to melt.
Combine the bicarbonate of soda and water in a bowl and then add to the melted butter and golden syrup, stirring well. It should foam up.
Pour the golden syrup mixture into the well in the dry ingredients and mix until well combined. Set aside.
For the cupcakes
Preheat the oven to 160C. Place pans in a muffin tin.
Add all ingredients except the apple to a large bowl and mix slowly at first, then fast for 2 minutes until it is all combined and is soft and creamy.
Chop the apples into small pieces (1 cm pieces) and add to the batter. Quickly fold together but do not over-mix.
Spoon the batter into the cases until no more than 2/3 full. Bake for 10 minutes until risen.
Remove from the oven and crumble some of the crumble topping onto each cupcake to make the crumb topping. Return to the oven and bake for a further 10 minutes.
Use the remaining crumble mix to make little Anzac biscuits to decorate the top. Simply form the mixture into little balls (3 cm diameter) and place on a lined tray. Increase the oven heat to 170°c and bake for 10 minutes or until golden.
For the buttercream
Place the butter in a bowl and beat until pale and fluffy. Sift over the icing sugar and mix until soft, then add the remaining ingredients and beat until smooth and fluffy (3-4 minutes).
Transfer to a piping bag and decorate the cakes with a swirl of buttercream.
Drizzle with a little golden syrup and top with a mini Anzac biscuit.
If you want a stronger golden syrup flavour, add more, but taste test before adding because the combination of golden syrup and sugar can get very sweet, very quickly.If you have the time, you can grate the apple.Option: Add half a cup of desiccated or shredded coconut to the batter when you add the apple.