Chocolate Chip Toffee Bars

2 1/3 cups flour
2/3 cup firmly packed light brown sugar
3/4 cup margarine or butter
1 egg slightly beaten
1 (12 oz.) package semi-sweet chocolate chips
1 (14 oz.) can sweetened condensed milk
1 (10 oz.) package toffee bits

Preheat oven to 350 degrees
In large bowl, stir together flour and sugar. Cut in margarine until mixture resembles coarse crumbs. Add egg; mix well. Stir in 1 1/2 cups chocolate chips. Reserve 1 1/2 cups mixture. Press remaining crumb mixture onto bottom of 13 x 9 inch greased baking pan. Bake 10 minutes. Pour sweetened condensed milk evenly over crust; top with 1 1/2 cups toffee bits. Sprinkle reserved crumb mixture and remaining 1/2 cup chips over top. Bake 25 to 30 minutes or until golden brown. Sprinkle with remaining 1/4 cup toffee bits. Cool completely. Cut into bars.