Preheat the oven to 180°C fan and line a 20cm (8-inch) square baking tin with baking paper.
Add the black beans, eggs, maple syrup or honey, oil and vanilla to a food processor or high-speed blender. Blend until completely smooth.
Add the cocoa powder, oat flour or wholemeal flour, baking powder and salt. Blend again until just combined.
Fold through half of the chocolate chips.
Pour into the prepared tin and smooth the surface.
Scatter over the remaining chocolate chips and dot the raspberries over the top.
Bake for 20–25 minutes, until the edges are set but the centre still has a slight wobble.
Leave to cool completely in the tin before slicing into 16 bites.
