In a large bowl cream the butter for 2 minutes, add the brown sugar and beat to combine.
Step 2
Sift in the flour and mix with a fork or clean hands to form a crumbly mixture.
Step 3
Pat evenly into the prepared pan. Bake for 10 minutes.
Step 4
To make the topping, in a bowl whisk the eggs, add the brown sugar and vanilla and whisk to combine, whisk in the sifted corn starch, salt and baking powder.
Step 5
Add the coconut, chocolate chips and nuts. Stir to combine.
Step 6
Pour the topping over the base and bake for 20-25 minutes until set and golden brown around the edges. Let cool completely before cutting.