Pre-heat the oven to 170 °C.
Line a 20 x 25 cm tin with high sides with baking paper.
Add pata kūteretere (softened butter) and huka one (caster sugar) to a medium bowl. Whip on high for 4-5 minutes. The mixture should be a pale colour and fluffy in texture.
Add in the tōhua hēki (egg yolks), wanira (vanilla) and tote (salt). Whip for another minute on high. Reserve the kahu hēki (egg whites) for the topping.
Add the puehu kānga (cornflour), kokonati (coconut) and puehu parāoa (flour). Fold together with a spatula until it all comes together.
Add into the prepared tin, press it evenly with your hands or a spatula.
Bake for 20 minutes until it is golden and remove from the oven.
Pull the cooked base from the oven, using a spoon press the base to the edge of the tin and gently flatten it out. This helps stop any of the filling from going down the sides of the tin. Leave to the side as you prepare the filling.