Mix the ingredients together in a pan, adding just enough water to wet down the other ingredients, set a stovetop burner in the medium heat range, and, stirring constantly, cook slowly until the temperature of the mixture is a carefully measured 310 degrees F. Cooking slowly is important for giving the Maillard reaction time to take place. (The Maillard reaction is what develops the butterscotch flavor). For measuring the temperature, I use an infrared surface temperature thermometer. There are many brands of these infrared thermometers on Amazon.
When the mixture is cooked, pour it immediately (not letting it harden) onto a flat surface that has been covered with a sheet of parchment paper, and let the mixture cool for, say, 20 minutes, until it is rock solid. Then crack it up with your food-gloved hands, transfer it to a blade type coffee grinder, and grind it into a fine powder. This may require several "transfer-grind" operations. Store the powder in a refrigerator, and use it as desired.