Step 2: KNO3 and Sugar
The main components of this composition are a brand of stump remover, which is 100% potassium nitrate (KNO3), and plain white table sugar.
In addition, I tried using different amounts of corn syrup and homemade rust powder. The rust was made by mixing steel wool (like these scrubbing pads) and vinegar, then letting it rust out over the course of 1-2 weeks.
Step 3: Mix Intimately and Caramelize
The mixture is volatile, and will violently ignite if brought in contact with a flame, so extreme caution needs to be used at this point.
When it's runny enough, it can be poured into a casing to cool down and solidify. I'm using these Mega-Block LEGOs. Watch out, it's hot!