Paula Sherman's Recipe For Butterscotch Pie

Paula Sherman sent me this recipe for Butterscotch Pie, and I want to pass it along.
At the Saltscapes Travel Expo, I met Paula and we were talking about the Cheticamp
area, and I mentioned that the best Butterscotch pie I had ever eaten came from the Co-op Artisan Restaurant in Cheticamp, and the gentlemen with Paula told me I was mistaken, that the best Butterscotch pie in Nova Scotia was his grandmother's. Paula told me she was given the recipe from his grandmother and that the pie was really good, and that his grandmother's secret to the recipe was not to leave the filling unattended while on the double boiler, stay right there and stir it. So I asked Paula to send me the recipe and I would pass it along on my blog. So you be the judge. If you are in Cheticamp try the pie from the Coop Artisan and then try Paula's recipe and let me know.

Butterscotch Pie
1/4c. margarine
1/4c. brown sugar
1 1/2 c. milk
2 eggs, separated
1/8 tsp. salt
1tsp. vanilla
1/4c. white sugar
1 baked 9" pie shell

Melt margarine. Add flour and salt. Blend in brown sugar. Add slightly beaten egg yolks and milk. Mix well. Place in double boiler over boiling water stirring constantly until mixture thickens and then cook 15 minutes longer. Cool; add vanilla.
Beat egg whites until stiff. Add sugar and beat until meringue forms peaks.
Pour butterscotch mixture into baked pie shell. Cover with meringue.
Return to 350 degree oven for a few minutes or until meringue browns. And enjoy!