Preheat the oven to 190°C.
Roll the pastry on a dusted surface to a 0.5cm thickness.
Line a 23cm deep-sided tart tin with the pastry and press into the edges.
Line the pastry case with paper and fill with baking beans or rice.
Bake the tart tin on a tray for 15 minutes.
Remove beans and paper then bake for another 8-10 minutes until golden.
Beat the butter and sugar together until pale and fluffy.
Crack in the eggs one at a time and beat well.
Fold in the ground almonds until combined.
Spread the raspberry jam evenly over the bottom of the cooled tart case.
Spoon in the almond mixture and smooth with a palette knife.
Dust with icing sugar and sprinkle over the flaked almonds.
Bake for 25-30 minutes until the filling is risen and cooked through.
Remove from the oven and set aside to cool slightly.
Serve slices with clotted cream and a drizzle of double cream.