Pour one cup of filling into pie shells.(some people cut the crimped edges off)
Bake at 350 degrees until filling is done, about 25-30 minutes or when filling bubbles slightly and turns lightly brown. A toothpick should come out clean.(A broom straw was used originally).
Allow pies to cool, then run a spatula around the bottom of the pies and stack them one on top of the other. Ice with carmel frosting on on sides and top.
ICING DIRECTIONS. Mix all ingredients together in a saucepan. Bring to a boil stirring constantly. Cook for two minutes.Cool to lukewarm. Add powdered sugar until thick enough to spread.If it get too thick add a little more milk.