Heat 1 tbsp butter and 1 tbsp sugar in a
large frying pan over medium heat until the
sugar starts to melt. Add apples, then cook
for about 5 mins, until nicely browned and
the sauce is a rich caramel. Leave to cool.
While the apples cool, make the topping.
In a food processor or using the tips of
your fingers, rub together flour, 85g sugar,
cinnamon and cold butter until the mixture
is crumbly and only pea-size pieces of
butter remain. Stir in 2 tbsp of hazelnuts.
Set aside in a cool place.
Heat oven to 180C/160C fan/gas 4.
To make the cake, place the remaining
butter and sugar in a bowl or food mixer
and beat until light and creamy. Add the
eggs one at a time, followed by the
vanilla extract. Add the flour, baking
powder, cinnamon and milk in two
goes, alternating between dry and wet
ingredients. When the mixture is well
combined, stir through the apples.
Grease a 20cm cake tin with removable
base and line the base with a circle of
baking paper. Spoon in the cake mixture,
smooth over the top with a spoon, then
sprinkle over the streusel topping. Scatter
with the remaining 1 tbsp demerara
sugar and hazelnuts. Cook in the oven
for 50 mins-1 hr or until a skewer inserted
into the cake comes out clean. Leave to
cool in the tin for 10 mins, then turn out
onto a baking rack, remove paper and cool.