Grease a 2-pt. pie-dish with butter.
Peel, core and slice the apples.
Place a layer in the bottom of the pie-dish and sprinkle with sugar, grated lemon rind and lemon juice.
Cover with thin slices of bread and butter.
Repeat until the dish is full, finishing with a layer of bread and butter.
Cover with greased paper.
Bake in a moderate oven (350° F., Gas 4) for 3/4-1 hr Turn out of the dish and dredge well with castor sugar before serving.