This is an old favorite of mine, reminds me of something my mother made me as a child.
6 cups of rice bubbles (check they are the gluten free variety)
40 mr mallows (gluten free marshmellows)
4 tablespoons butter
In a large bowl melt the butter and marshmellow (1 minute on high in the microwave). Stir in the rice cereal and press into a buttered pan.
Allow to cool then cut into squares.
Great for lunch boxes.