Pre-heat your oven to 190°c (or 170°c for a fan assisted oven or Gas Mark 5) and grease a 11x7 inch baking tin generously with some margarine/butter. Set aside. Remove your pre-made pastry from the fridge and roll on a floured surface to around 5mm thick. Transfer to your pre-greased tin, pushing the pastry into the edges. Trim the excess and line the pastry with some greaseproof paper before filling with baking beans. Blind bake the pastry for 10 minutes to give the bottom a head start and avoid a soggy pastry. Following the blind bake - and once cool enough to do so - remove the baking beans and top the pastry with the Raspberry Jam, evenly spreading over the pastry.
In a large bowl, cream the margarine and sugar until light and fluffy.
Add the ground almonds and self-raising flour, mixing together before adding the eggs one at a time, continuing to mix to make a smooth batter.
Spoon the batter on top of your jam-topped pastry and spread. evenly, ensuring to get right to the edges and corners. Top with a generous handful of flaked almonds.
Bake in your pre-heated oven for 20-25 minutes until golden and spongy in appearance.
Once completely cool, using a sharp knife, cut into individual slices.