1 can (14 oz) sweetened condensed milk (not evaporated)
1 cup packed brown sugar
1/2 cup butter
1/4 cup milk
1 bag (11.5 oz) milk chocolate chips (2 cups)
Line 13x9-inch pan with foil. Spray foil with cooking spray. Place 30 of the crackers in bottom of pan.
In 2-quart saucepan, mix condensed milk, brown sugar, butter and milk. Cook over medium heat until butter is melted, stirring frequently. Increase heat to medium-high; heat to boiling. Boil 5 minutes, stirring constantly.