Bring first 4 ingredients to a boil over high heat in a 2-quart saucepan (nonstick works best) and stir constantly until temperature on candy thermometer reaches 300 degrees (approximately 10-13 minutes). Pour into an ungreased 10x13 inch baking sheet and spread evenly to coat. Will begin hardening immediately so move quickly.

Sprinkle milk chocolate chips evenly over hot toffee and wait 1 minute till they begin to melt. Spread softened chocolate evenly over entire pan (like frosting) and chill for 2 hours. Slam pan once on counter to crack and break apart into about 2-inch or smaller pieces. Store chilled in a sealed plastic bag or container and let get to room temperature before serving.