Preheat the oven to 180 degrees C and lightly grease 12 cupcake cases.
Gently melt the butter over low heat and cool. Beat an egg and whisk the butter into it till combined. Whisk in the orange juice, rind and sugar.
In a large bowl, sift together the flour, soda bicarb, baking powder, spices and salt. Make a well in the centre and pour in the liquid mixture. Mix lightly until just combined. Now tip in the fruits and walnuts and mix (again, do not over mix).
Fill the cups three quarters full and bake for 20-25 minutes till the tops are golden and a toothpick when inserted comes out clean. Cool on a rack.