In a small bowl, combine the cracker crumbs, brown sugar, pecans, and cinnamon. Stir in butter; set aside.
Prepare cake mix according to package directions.
Pour half of the batter into a greased 13x9-in. baking pan. Sprinkle with half of the graham cracker mixture. Carefully spoon the remaining batter on top. Sprinkle with the remaining graham cracker mixture.
Bake at 350° for 30-40 minutes or until a toothpick inserted in the center comes out clean.
For the glaze-combine confectioners' sugar and milk; drizzle over coffee cake.
For my international readers, if you don't have graham crackers for the streusel, digestive biscuits work just as well. Basically, just try to find a sweet simple cracker.