Mix the biscuits, butter and allspice together, then press into the bottom and sides of a well-greased 23 cm./ 9 in.flan tin.
Chill in the refrigerator for 10 minutes.
Mix all the remaining ingredients, except the cinnamon, together.
Spoon into the biscuit crust and dust with the cinnamon.
Put into the oven preheated to warm (170°C/325°F or Gas Mark 3) and bake for 40 minutes, or until the filling is set.