- 12 graham crackers, broken into quarters
- 1/2 cup butter
- 1/2 cup margarine
- 1/2 cup white sugar
- 1/4 cup chopped walnuts, or to taste
- 1 (12 ounce) package milk chocolate chips
- Preheat oven to 350 degrees F (175 degrees C).
- Line a 10×15-inch baking sheet with graham cracker quarters.
- Bring butter, margarine, and sugar to a boil in a saucepan, stirring constantly, until sugar is dissolved, about 3 minutes. Pour butter mixture over graham crackers and sprinkle with walnuts.
- Bake in the preheated oven until butter is browned and nuts are toasted, about 10 minutes. Immediately transfer toffee bars from the baking sheet to a platter lined with aluminum foil or wax paper.
- Melt chocolate chips in 2 batches in a microwave-safe bowl in 30-second intervals, stirring after each melting, for 1 to 3 minutes (depending on your microwave). Drop spoonfuls of melted chocolate over each toffee bar.