Marlborough pie is found in an English cookbook from 1660, and was popular in New England through the mid-1800s.
Make a pie crust. Prick the crust with a fork, and/or cover it with a circle of parchment paper and sprinkle it with pie weights, then blind-bake the crust until it just starts to brown (10-15 minutes).
Peel and core one pound of firm, tart apples (about 3), then coarsely grate (or finely chop or thinly slice) them.
Melt 2 Tbsp butter in a saucepan, add 3 Tbsp of lemon juice and 3 Tbsp of sherry (or Port or similar spirit, optional), then add the apples and simmer, stirring occasionally, for about 10-15 minutes until the apples are stewed and most of the liquid has evaporated.
Season to taste: perhaps 1/4 tsp salt, and 1 tsp total of a blend of “warm” spices like cinnamon, nutmeg, ginger, allspice, cloves, pepper etc — what medieval cooks might have called “fine powder” or what Americans now call “pumpkin pie spice.”
Set the apples aside to cool for a few minutes.
Combine 3 eggs, 1 cup of half-and-half (or equal parts milk and cream, or just cream), and 3/4 cup of sugar, and whisk them together.
Stir together the apples and the custard, then pour them into the pie shell.
Bake at 350° for about 40 minutes, rotating half way through. At around 30 minutes, start checking every five minutes to see if the top is lightly browned and the custard has set — it’s okay for the center to still jiggle, but it shouldn’t be wet.
See also: Pumpkin pie.