In a large bowl place crushed biscuits, macadamia nuts, coconut, butter and ½ cup of the caster sugar. Mix until all ingredients are completely combined.
In a 26cm round spring form pan press crumbs in to the bottom and up the sides to form your shell. Press firmly, you may wish to use the bottom of a glass to assist you. Place pan in the fridge to chill until your filling is ready.
Place gelatine leaves in a bowl and cover with cold water. Allow to soften. Once softened, squeeze out excess water and place in a small saucepan, add 3T of the softening water. Over low heat melt the gelatine. Take off heat and set aside
Place cream cheese, sugar, lemon myrtle and vanilla in the bowl for your stand mixer. If not using a stand mixer place in a large bowl. Beat until mixture is very smooth and creamy.
Slowly add the, now cooled (but still liquid), gelatine to the cream cheese mixture, turn the speed up and keep beating on high for 5 minutes. Reduce speed and slowly pour in the cream. Continue to beat until well combined.
Remove shell from the fridge and pour in cream cheese mixture. Place cheesecake in fridge to chill and set. Once set it is ready to serve.