9 inch graham cracker pie crust

4 egg yolks

1/2 cup key lime juice

1 14 oz can sweetened condensed milk

4 tsp lime rind

1 1/2 cups whipping cream

1 1/2 tbsp sugar

1/2 tsp. vanilla

1 1/2 tsp. dark rum (optional)

Whisk egg yolks until blended; whisk in lime juice.  Add milk, whisking until blended.  Stir in lime rind.  Pour into pie crust and bake at 350* for 12-15 minutes or until set.  Remove from oven and cool on wire rack.  Cover and chill 8 hours.

Beat cream until foamy, gradually add sugar, beating until soft peaks form.  Gently stir in vanilla and, if desired, rum.   Spoon on top of pie.