These are shockingly easy to make yourself, considering how expensive a bag of branded candy toffee bits (Heath, Skor, etc.) can be.
- 1/2 c. butter
- 1/2 c. sugar
- 2 T water
- Pinch of salt
Bring it all to a low boil until it hits around 300 degrees. If you don't have a thermometer, go by color - be aware that this will go from "lovely dark caramel" to "Cthulhu destroyed my favorite saucepan with his bilious rage" in a flash. Keep the boil gentle and an eye on the action.
Spread it out on a cookie sheet covered with Silpat or parchment paper and let it cool a bit, then chill it in the fridge. Break or smash into desired size. This will make a LOT of toffee bits. Seems like about double the single cup you'd expect given the ingredients, on account of the smashy breaky non-solid nature of the end product.