Brain Matter Jello. Cherry Jello, marshmallows, and a mason jar. Rip up and twist the marshmallows. Make sure they are sticky. Dip them into the Jello Powder and put it into the jar as is. Then make the jello in a seperate container as the box says. Then pour the mixture over the marshmallows. They will float to the top. Cover and set aside for 3 hours. The jello will set perfectly and the marshmallows will take on a jello texture too. 1 box & 6 marshmallows makes 2 jars. Great for Halloween...