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Stack of 3 mars bar squares with glass of milk.

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. #nobake #ricekrispies #ricebubbles #nobake #marsbars #chocolatebars #ricekrispies #easy #treats
Course Dessert
Cuisine Australian, Canadian
Keyword Mars Bar Slice, Mars Bar Squares, Rice Krispie Treats, Rice Krispies
Prep Time 10 minutes
Resting 2 hours
Total Time 2 hours 10 minutes
Servings 16 squares
Calories 183kcal


  • ½ cup unsalted butter
  • 4 53 gram Mars bars chopped
  • 3 cups Rice Krispies aka Rice Bubbles
  • 1 cup milk chocolate chips or chopped milk chocolate


  • 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.
  • Once melted, turn off the burner and stir in the Rice Kripies/Rice Bubbles.
  • 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.
  • 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. *


  1. For gooier bars, use 2 ½ cups Rice Krispies/Rice Bubbles. 
  2. Once the chocolate is about 80% hardened score the top of the chocolate with a thin, sharp knife where you plan to slice the bars. This helps preven the chocolate from cracking when you cut the bars.
  3. Store in an airtight container at room temperuature 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. 
  4. Nutrition info is based on 1 square, with the pan sliced into 16 pieces. 


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