Preheat oven to 350 degrees. In a large bowl mix the flour and sugar together. Cut in butter until the mixture is coarse crumbs, Add beaten egg and mix well. Stir in 1 1/2 c. chocolate chips and nuts. Reserve 1 1/2 c. of that mixture. Press the rest into a greased 9x13 pan. Bake for 10 minutes. Pour the sweetened condensed milk over the top in an even layer. Top with 1 1/2 c. toffee bits. Sprinkle reserved crumb mixture on top, followed by the remaining chocolate chips. Bake 25-30 minutes or until golden brown. Sprinkle remaining toffee bits on top, the cool completely before cutting into bars.