Preheat the oven to 175C/350F.
Line and grease a 20cm/8inch cake tin.
Combine chickpeas, coconut flour, almond meal and baking powder in a blender and blend until fine (the chickpeas will be broken down).
In a mixing bowl of a stand mixer with a whisk attachment fitted, whisk the egg whites on medium until medium peaks form.
Turn mixer off and add honey and zest and whisk on medium/high again.
With mixer on medium/high, add egg yolks 1 at a time.
Add dry ingredients and remaining wet (milk and orange juice) alternatively in 3 lots with mixer on low.
Beat on high for 30 seconds.
Pour cake mixture in prepared cake tin.
Sprinkle the top evenly with pistachios.
Bake for 40 min, or until cooked through.
Rest in tin before removing.
Can be served warm or cold and with whipped coconut cream.
Drizzle cake with honey before serving.