Heat oven to 160C/140C fan/gas 3.
Grease a 2lb loaf tin and line the base and
ends with a long strip of baking paper.
Beat together the butter, sugar and
vanilla until pale, then beat in the eggs,
one by one. Tip in the flour, cinnamon
and yogurt. Peel, core and chop apples
into small chunks, then add to the bowl
and mix everything together with a
Scrape into the tin, smooth the top and
scatter the walnuts down the middle.
Bake on a middle shelf for 1 hr 20-30 mins
until a skewer poked in comes out clean.
Cool in the tin.
To decorate, put the toffees in a small
saucepan with the double cream. Gently
heat, stirring, until toffees have melted
into a smooth caramel sauce. Cool for
about 1 min while you gently turn out the
cake. Slowly drizzle the toffee sauce over
the top of the cake. Scatter immediately
with the extra walnuts – they should stick
where they hit toffee. Leave for 10 mins
before serving. Best fresh but will keep
in an airtight tin for 3-4 days.