KNO3 8g + powdered sugar (sucrose) 4g, mixed in solution ~40ml hot water
Since reducing the particle size gave better results, we decided to try mixing the components in solution for the ultimate molecular level mixing. We disolved the KNO3 in hot water, added sugar, and then poured the solution into a plastic tray and left it to dry for 5 days at 30% relative humidity, 22°C, with periodic mixing.
We we lit it it burned very fast, by far the best so far.