Heat oven to 180C/160C fan/gas 4.
Cream the butter and sugar together
until well blended and smooth.
Gradually beat in the banana, vanilla
extract and egg. Add the
zest. Mix well with a wooden spoon
until thoroughly blended.
In a large bowl, mix the flour, salt,
baking powder, oats, coconut,
walnuts and sultanas or chocolate
chips. Stir the dry ingredients into
the wet and mix thoroughly until a
thick dough is formed. Line a baking
sheet with parchment. Drop heaped
tbsps onto the sheet, leaving a 5cm
(2in) space around each one, and
press down lightly. Bake for 15-20
mins until lightly browned. Cool.