Heat oven to 200C/fan 180C/gas 6. Grease
a roasting tin (30x20cm) with butter, dust with a little
flour, then set aside. Peel, core and slice the
apples into rings, then toss in a little lemon
juice to stop them going brown.
Tip the cream and butter into a saucepan,
bring up to the boil, then set aside. Whisk the
sugar with the eggs until they thicken and
turn pale, about 3 mins. Whisk the buttery
cream into the eggs, then fold in the flour
until completely smooth.
Pour the batter into the prepared tin and
arrange the apple slices over the top. Scatter
over the blackberries, then sprinkle with the
remaining sugar. Bake for 50 mins-1 hr until
golden and beginning to pull away from the
sides of the tin. Leave to cool in the tin and
serve cut into squares.