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Stack of three Mars Bar Slice squares, one on top of another
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5 from 2 votes

Mars Bar Squares

What do you get when you melt together chocolate bars and mix them with Rice Krispies? These delicious, no-bake Mars Bar Squares AKA Mars Bar Slice. They're gooey, crunchy, topped with milk chocolate and absolutely addictive.
Prep Time10 minutes
Resting2 hours
Total Time2 hours 10 minutes
Course: Dessert
Cuisine: Australian, Canadian
Keyword: Mars Bar Slice, Mars Bar Squares, Rice Krispie Treats, Rice Krispies
Servings: 16 squares
Author: Fiona Dowling

Equipment

  • 8x8 inch (20x20 cm) pan

Ingredients

  • 1/2 cup unsalted butter (112 grams)
  • 4 Mars bars (53 grams each) chopped
  • 3 cups Rice Krispies (about 90 grams) aka Rice Bubbles
  • 1 cup milk chocolate chips (about 200 grams) or chopped milk chocolate

Instructions

  • Lightly grease an 8x8 inch (20x20 cm) square baking pan.
  • Add the butter to a large saucepan and gently melt the butter over low heat.
  • Add the chopped Mars bars to the butter and gently stir the mixture as the Mars bars begin to melt.
  • Continuously stir the mixture until smooth. If the butter and chocolate bars start to separate, remove from the heat and whisk until smooth. Stir constantly to avoid burning.
  • Once melted, turn off the burner and stir in the Rice Kripies/Rice Bubbles. Feel free to use 2 1/2 cups (instead of 3 cups) for gooier bars.
  • Spoon the batter into the prepared pan, and gently press it down. You can lightly grease a spatula or spray your hands with non-stick cooking spray if you find the mixture keeps sticking to the spatula or your hands.
  • Add the chocolate chips/chopped chocolate to a heatproof bowl. Microwave on medium power for 45-second intervals, stirring between each. Once the chocolate is almost melted, stir until smooth. Alternatively, melt in a double boiler over low heat. Ensure that the water underneath does not touch the bottom of the bowl with the chocolate.
  • Spread the mixture over the bars and let sit for 2 hours at room temperature, or until the chocolate is hardened before slicing into bars. When the chocolate topping looks about 80% hardened, use a thin knife to trace along the top where you plan to slice the bars. This makes slicing easier because the chocolate topping won't crack.

Notes

  1. Rice Krispies: For gooier bars, use 2 1/2 cups Rice Krispies/Rice Bubbles. 
  2. Storage: Store in an airtight container at room temperature for up to 4 days. I do not recommend storing in the fridge or freezing the bars because the chocolate topping can discolor, and they can end up getting too hard and crunchy. If you choose to freeze them, thaw in the fridge overnight then let them sit on the counter at room temperature before enjoying. 
  3. Nutrition: Nutrition info is based on 1 square, with the pan sliced into 16 pieces. It is an estimate only

Nutrition

Calories: 183kcal | Carbohydrates: 22g | Protein: 1g | Fat: 11g | Saturated Fat: 5g | Cholesterol: 17mg | Sodium: 36mg | Potassium: 7mg | Fiber: 1g | Sugar: 8g | Vitamin A: 552IU | Vitamin C: 3mg | Calcium: 15mg | Iron: 2mg