Stir together flour and brown sugar.
Cut in butter until mixture resembles coarse crumbs.
Add egg and mix well. Using hands works well.
Reserve 1 ½ cups of this mixture and press remaining into a greased 9x13 inch pan.
Bake for 10 minutes at 350.
Pour milk over hot crust and top with Andes mint chips.
Stir in 1 ½ cups chocolate chips into reserved crumb mixture.
Sprinkle remaining crumb mixture over top plus remaining chips.
Bake 25-30 more minutes, edges should start browning and bubbly, remove from oven
Add whole Andes Creme de Menthe Candies, M&Ms, Mint M&Ms and let bars cool. They taste amazing still warm!!!