Make the crust: in a bowl, whisk together the flour, salt and sugar. Rub in the cold butter to form crumbs. Sprinkle ice water on top and stir with a fork until dough just starts to come together (you may need a little more ice water).
Very briefly knead the dough then press into a disk and wrap in plastic. Refrigerate 30 minutes. Meanwhile, preheat oven to 180 degrees C.
In a bowl, toss the apple slices with brown sugar and lemon juice. Unwrap the dough and place on a sheet of wax paper. Cover with another sheet of paper and roll out the dough to a 25cm circle. Transfer the dough carefully to a tart pan, discarding the paper.
Prick the dough all over with a fork. Arrange the apple slices over it and sprinkle with raspberries. Pour any accumulated juices over the fruit then bake 40 minutes. Serve at room temperature.