Nutty Graham Cracker Bars

In a medium saucepan, combine the egg, 3/4 cup of unsalted butter, granulated sugar, and 1/4 cup of milk.
Cook and stir over medium heat until the mixture comes to a full boil.
Remove from heat and stir in the toasted pecans and graham cracker crumbs.
Allow this mixture to cool for 30 minutes.
Line a cookie sheet with foil.
Place six of the graham cracker rectangles side by side on the prepared cookie sheet to create a 10x7-inch rectangle.
Spread the filling over the graham crackers, then top with the remaining six graham cracker rectangles.
Cover the bars lightly with plastic wrap and chill for at least 4 hours or until the filling is firm.
For the icing, in a small bowl, beat 1 tablespoon of softened unsalted butter until smooth.
Gradually whisk in the powdered sugar and enough of the 2 to 3 teaspoons of milk to reach a thick drizzling consistency.
Drizzle the icing over the bars and let it stand until the icing is set.
Cut the chilled bars into 24 servings (1 bar each).