Wash barley, cover in water, about 2 inches above, and leave in a pot over night, covered with a lid.
The next day, put the pot over low heat and cook it until the water is absorbed almost completely.
During boiling don't mix the barley just try and gently shake the pot from time to time so that the grains won't stick to the bottom of the pot. I recommend using a non stick pot.
After the water has evaporated almost completely, add sugar and salt, mix and cook for another 10-15 minutes or until the water has evaporated completely.
Turn the heat off and cover the pot with a lid. Leave it to cool.
Add finely chopped nuts, orange zest, cinnamon and rum essence and mix until well incorporated.
Mix the biscuits and ground walnuts and use the mix to decorate. If you choose to make individual cups, add the cooked barley to each cup, create a small dome and sprinkle the biscuits walnuts mixture on each cup. You could dust some icing sugar too at this point, if you opted for. Add sprinkles and sour gummy candy.
Serve your barley breakfast pudding with a glass of milk or next to your coffee.