SOUTHERN SWEET POTATO PIE

Bake 4 large sweet potatoes, then scrape the inside from them, and beat into it lightly with a fork 2 tablespoons of butter, 2 tablespoons of sugar, 3 well-beaten eggs, 1 cup of warm milk, a saltspoon of salt, and a pinch of mixed spice. Line a baking dish with pastry, fill with the potato, and bake for twenty minutes.