Set the sugar in a deep, light colored heavy bottomed pot, squeeze a few drops of lemon onto it and stir to mix in the lemon. Spread the sugar in an even layer and cover the pot.
Turn the heat on to medium and cook, stirring quite often as the sugar melts and then turns to a light brown liquid. Make sure you are stirring frequently with a long wooden spoon to avoid any hot spots or sugar burning, use the back of a spoon to break up any lumps of sugar.
Keep stirring frequently until all of the sugar is melted and has turned an amber color - check it by pressing the wooden spoon against the bottom of the pan to check for any scratching (those are unmelted sugar granules). Keep the heat steady and under 360 F, above it and the caramel will burn. You're looking for a toasty shade of amber.
Warm up the heavy cream, and slowly, while stirring, pour into the pot. Be careful because it will boil up. Add the butter, molasses, salt and spices.
Stir until the butter has melted then turn off the heat and stir in the vanilla.
Let cool to room temperature then pour into a sealable jar.
Store in the fridge, it’ll keep for up to a month.