Preheat the oven to 170°C (350°F) and lightly grease a 20 x 20 cm baking tin.
Blend all ingredients — except the chocolate chips — in a food processor until completely smooth and creamy. Take your time blending to ensure the batter has no lumps.
Stir in the chocolate chips.
Pour the batter into the prepared baking tin and smooth the surface.
Bake for about 20 minutes, or until a skewer inserted into the centre comes out mostly clean but the cake is still slightly soft.
Cool completely in the tin, then refrigerate for at least 2 hours or overnight to firm up.
Slice into squares and serve chilled or at room temperature.