Heat oven to 190C/170C fan/gas 5.
Line a 900g/2lb loaf tin with baking
parchment. In a large bowl, mash
together the bananas and the sugar
with the back of a fork. Add the eggs
and mix well with an electric hand
whisk until fully incorporated, then
add the butter and mix for a couple
mins more to blend everything
together. Sieve in the flour and
baking powder and fold together
with a spatula, then add the
walnuts and chocolate chips. Give
everything one final mix before
tipping into the lined loaf tin.
Bake for 1 hr 5 mins or until a
skewer inserted into the middle
comes out clean. Leave to cool
slightly in the tin, then turn
out and serve cut into thick
slices, either warm or at room
temperature. Any uneaten
cake will keep in an airtight
container for up to 3 days.