Pre-heat your oven to 170 °C on the bake setting.
In to a large bowl, whip the pata kūteretere (softened butter), huka hāura (brown sugar) and wanira (vanilla) for 4-5 minutes until light and fluffy. Add the puehu parāoa (flour) and kōkō (cocoa). Gently stir until a dough forms.
Roll the mixture in to 20 equal balls. Place them on to a baking tray and press them down until they are 2cm high (these biscuits melt down when they bake so don't squash them down too far).
Bake in the pre-heated oven for 9 minutes. They will look soft when they come out, this creates a fudgy texture.
Remove from the oven and use a rounded teaspoon (measuring spoon) to press hollows in to the pihikete (biscuits) while they are warm.
Press each peanut butter truffle in to the groves of the warm biscuits, work gently. Prepare the tiakarete (chocolate).