Start by preparing the pastry; cream together the butter and sugar, beat in the eggs and finally the ground almond and gluten free flour. Wrap in cling film and refrigerate for 30 minutes. Roll the dough on a lightly dusted surface and line a 25 cm loose bottom tart tin, spread the bottom of the pastry with the raspberry jam. To prepare frangipan, cream together the butter and sugar, beat in the eggs. Mix together the ground pistachios, almonds flour and lemon zest, fold into the butter mixture. Fill the tart with the frangipan and start baking at 175֯`c for 10 minutes, take out of oven and carefully cover with raspberries. Return to cook for further 30 minutes until just cooked. Allow cooling completely before serving