Today, Mr 5 was insisting he wanted to make some 'concrete you can eat', and was dictating a recipe. (Hey, it's not a recipe I made up, so I'm counting it!). The first version contained chocolate for the stones, baking powder for the cement, and water. I had him try a little bit of baking powder to see what it tasted like, and he modified the recipe to use icing sugar instead. I asked what we would do with the concrete, and he decided it should go on crackers, so I found some Digestive biscuits.
The concrete wasn't set hard when we tried them for afternoon tea, but they seem to have been a success!
Is it wrong that I'm thinking of doing some structural testing with different blends of concrete mix? (I think almond flour might make a nice sand substitute..)