This Mars bar slice is made with rice krispies mixed with melted Mars bars, and with a chocolate layer on top. Caramel, nougat, chocolate, and rice krispies! Easy recipe & no bake too. Kid friendly (with supervision!), and great as edible gifts. EASY - Very easy recipe. I made this often as a little kid (with adult supervision of course). US based cup, teaspoon, tablespoon measurements. Common Measurement Conversions. Weight measurements are recommended for accurate results.