Preheat the oven to 350 degrees. Grease an 8x8-inch baking pan.

Soften butter for a couple of seconds in the microwave, or however, you like. Beat brown sugar, softened margarine, and flour in a medium or large bowl until nice and creamy or well blended. Press evenly on the bottom of the 8x8 pan. Bake at 350 degrees for 25 minutes or until lightly golden. Remove from oven while preparing to fill.

In a small pot, heat sweetened condensed milk and margarine, stirring constantly at low to medium heat for 5-10 minutes. Pour and spread evenly over the cooled crust. Bake at 350 for 15 minutes or until lightly golden.

Sprinkle milk chocolate chips evenly all over the top. Bake for 2 more minutes or until the chocolate is shiny. Remove from oven and spread chocolate all over the top. Sprinkle toffee bits all over top. Tap lightly into the chocolate. Cool completely, then cut into bars.