Preheat oven to 375 degrees. Line a cookie sheet with aluminum foil. Arrange crackers on foil, single layer, touching.
In a small saucepan, bring butter and brown sugar to a full boil, stirring occasionally. Remove from heat and stir in baking soda. Pour mixture over crackers and bake 6-8 minutes.
Remove from oven and immediately sprinkle chocolate chips over. Spread evenly as they melt. Refrigerate and break into chunks when cool.
Store covered at room temperature.