Mix the heavy cream, sugar, and syrup in a pot and bring to a boil.
Boil on medium heat. Stir once in a while. The mixture bubbles a lot.
While boiling, prepare a tray with small paper candy cups or foil cups that are meant for chocolate truffles.
Your toffee is ready when the temperature is around 257-266F, (125-130C). It takes 30-50 minutes to reach this temperature, this depends on your stove and type of pan. You can test by dropping some in a glass of water, if it has a ball shape and you can form it with your fingers then the mix is done.
Take the mixture off the heat and add in the butter, almonds, and salt. Stir.
Put toffee mix in your small cups with the help of teaspoons. Let the candies cool down. They set quite quickly in the fridge.
Notes
Temperatures for consistency:
257 F (125C)- a bit soft and chewy toffee
280 F ( 140F)- harder, but still slight chewiness on the inside.
315 F ( 155C)- hard candies
Store in the fridge for up to 3 weeks. The candies can be frozen up to 3 months. The amount of small candies you get from this amount varies depending on your paper cup size.