Line cookie sheet with nonstick aluminum foil (or use regular foil and spray generously with nonstick cooking spray.)
Cover cookie sheet with one layer of saltine crackers.
In a medium saucepan over medium high heat, bring butter and brown sugar to a boil, stirring continuously for about two minutes (it should be bubbly.)
Remove from heat, stir in one teaspoon pure vanilla extract.
Pour toffee mixture over crackers, then bake for 6 minutes.
Remove from oven, sprinkle top of warm crackers with milk chocolate chips.
Allow chocolate to soften for a minute or two, then spread chocolate evenly on top of crackers. Now is the time to add sprinkles or chopped nuts to the top.
Allow to cool, then break up into bite size pieces.
Notes
You can speed the cooling process by placing the tray into the freezer.