Testing - Potato-Apple Cake

Food in England, Dorothy Hartley, p 370

1 - It turned out well. Ben and I agree that it is likely more of a side dish than a main dish. I did not pinch in the butter at the correct moment for the crust, and I felt it was a bit tough. I will make it again in the correct sequence, and may attempt a future iteration with baking powder in the crust to make it more bread-like.
In fact, I also made it in a pie plate just as a pie, with the bottom a little thinner than the lid. I'd like to make it more like a pithivier and smaller so that it is a bit like a dome - I think it would look better and the sugar and butter would disperse more readily at the final stage.
OH! and the time is incorrect. I will change it as it took much longer to bake than I'd anticipated.

1 lb potatoes
1 oz butter
2 tsps sugar
1⁄2 tsp salt
1⁄4 tsp ginger powder (or 1⁄8 tsp ground cloves or 1 tsp cinnamon or a blend)
4 oz flour (3⁄4 cup?)
2 large apples, sliced
3 Tbsps very soft butter
2 Tbsps sugar

1. (Ms. Hartley's instructions, but see mine, in point 2. : Peel and boil the potatoes until quite soft. Mash with the oz of butter, the sugar and the spice. Add enough of the 4 oz of flour to make a dough that will roll out smoothly onto a floured surface.)
2. "1-Peel and boil the potatoes until quite soft. Drain and allow to cool completely, preferably for several hours in the refrigerator. Mash thoroughly, until almost completely broken down but not so much that it becomes a paste. 2-Combine the sugar, salt, spice and flour. Pinch in the cold butter until it forms pea-sized granules. Mix in the mashed potato and work until it forms a ball."
3. Divide into two balls. Roll out into thickish (?) rounds (she says As if making rather thick pastry), the second larger than the first to fold over the apple filling (rather like the Pithivier).
4. Cover the bottom round with an inch layer of sliced apple.
5. Damp the edges of the bottom round, lay the top round of dough on top and press and pinch the edges together. Mark the top with a broad X.
6. Bake in a hot oven (400-450F?) 425F until brown outside and the apple soft inside, for (30?) 50 minutes.
7. When baked, cut a hole on top to make a lid and lift off carefully, about 2 inches in diameter to avoid spilling any juices. Quickly add the extra butter and sugar, replace the lid and put back in the oven for 5 minutes to give the butter and sugar time to melt.
8. 'It is best to 'carve' the pudding with two forks, pulling the pudding into four farls (where you marked the X on top).'