In a large bowl, combine flour, sugar and cocoa; cut in butter until mixture resembles coarse crumbs.
Pre-heat the oven to 350°F.
Stir in eggs and set aside 1-1/2 cups for topping.
Press remaining crumb mixture into a greased 13-inch x 9-inch baking pan.
Place in pre-heated oven and bake for 6 to 8 minutes or until set.
Meanwhile, in a saucepan, combine milk and 1 cup of chocolate chips; cook and stir over low heat until melted.
When crust has finished baking, remove from the oven (do not turn off oven); carefully spread milk and chocolate chips mixture over the crust.
In a small bowl, combine reserved crumb mixture with nuts and remaining chips.
Sprinkle nuts and chips mixture over chocolate layer.
Return to pre-heated oven and bake for another 15 to 20 minutes or until top is set; chips will not look melted.
Remove from oven and cool before cutting.
