To make the pastry, cream together the butter and sugar by hand or using a mixer. Sieve the baking powder and flour together and stir into the butter mix with the salt, then slowly pour in the cream until well mixed. Leave to chill in the refrigerator for about 30 minutes.
Roll the pastry out on a floured table to about 3mm thick. Cut a disc large enough to line an 18 x 3cm deep loose-b