Graham Streusel Coffee Cake

1 1/2 c. graham cracker crumbs
3/4 c. brown sugar
3/4 c. chopped nuts
1 1/2 tsp. cinnamon
2/3 c. butter, melted
1 (18 1/2 oz) pkg. yellow cake mix
1/2 c. confectioners' sugar
1 T. milk

Combine cracker crumbs, brown sugar, nuts, cinnamon, and melted butter; set aside. Prepare cake mix according to package directions. Pour 1/2 of the batter in a greased 13X9 baking pan. Sprinkle 1/2 of the cracker mixture; spoon the remaining batter on top; sprinkle with balance of cracker mixture. Bake at 350 degrees for 35-40 minutes. Cool. Combine powdered sugar and milk. Drizzle over cake.