Combine the ground graham crackers and 2 teaspoons of the sugar.
Melt 9 tablespoons of the butter. Stir the butter into the ground graham cracker.
Press the mixture into a 9.5 or 10 inch pie pan.
Refrigerate for at least 30 minutes.
Chop 2 cups of the pecans. Set aside.
In a saucepan, melt the remaining 3 tablespoons of butter on low heat.
Add the sugars, cornstarch, cream, and corn syrup. Cook until the sugars melt. Remove from heat.
Beat the eggs with the vanilla and rum (if using) in a small bowl. Mix a couple of tablespoons of the hot mixture into the eggs to temper the eggs. Gradually, whisk or stir the eggs and add to the hot mixture. Return to heat. Cook until the mixture starts to thicken.
Stir in 1-1/2 cups of the chopped pecans. Cook until the mixture coats the pecans.
Pour into the pie shell.
Decorate with the remaining whole pecan slices.
Bake in a preheated oven at 350 degrees Fahrenheit for 50 minutes.
Allow the pie to cool completely before slicing.
Serve with Vanilla Ice Cream, Butter-Pecan Ice Cream, and/or whipped cream.