Place the walnuts on a lined baking sheet and toast at 400F/200C for 5 minutes. Leave to cool, chop and set aside 1/3 cup to top the bread with later.
In a large bowl, sift together the rice flour, almond flour and baking powder. Mix in the salt.
In a second medium-sized bowl, stir together the coconut sugar, lemon and orange zest. Rub the zest into the sugar with your fingertips to really bring out the flavour. You know you’re doing it right when the sugar becomes moist.
Stir in the agave syrup, orange juice, coconut milk and melted coconut butter. Beat until combined.
Mix in the psyllium husks.
Add the wet ingredients into the dry ingredients and beat with a hand mixer until just combined.
Stir in the cranberries and chopped walnuts with a dry spatula.
Lightly grease a loaf tin with cooking spray and scoop the bread dough into it. Smooth down the top with a spatula.
Preheat the oven to 180C/350F and bake the bread for 40-50 minutes.
Leave the bread to cool completely before spreading the coconut butter on top, sprinkling with lemon zest and topping with the toasted, chopped walnuts.