Boil the brown sugar and butter together until soft. Beat the egg yolk well and add it to the flour, then add the milk. Beat this until very smooth. Combine with the sugar mixture and cook until the mixture thickens. Remove from fire and add salt and flavoring. Pour into a pastry-lined pan. Bake at 450-F for 10 minutes; reduce the heat to 350-F and bake 30 minutes. Cover pie with a meringue made by beating the white of the egg stiff and adding 1 tsp sugar. Return pie to oven to brown meringue.

Cook Book - Fine Old Recipes, Culinary Arts Press, 1936.