Warm the heavy cream and set aside.

Pour the sugar into a heavy bottomed pot and set over low heat.

Squeeze the lemon over the sugar and use a wooden spoon to stir it until it’s like wet sand. Smooth the sugar into an even layer.

Turn the heat up to medium low and cover with a lid.

After 2-3 minutes, check on the sugar: once you see it starting to melt you can start stirring it and then smoothing it into an even layer. Cover the lid and leave it for another 2 minutes.

Depending on how quickly your pot and burner heat, the sugar might take another couple of minutes or more to start melting fully and darkening in color.

Once you start to see some of the sugar turning amber colored, leave the lid off and stir the sugar as needed so that it melts and caramelizes evenly.

It’s ok if some of the sugar hardens and becomes rock-like, that will melt too. You can press those bits with the back of the wooden spoon to encourage them on.

Once all of the sugar is melted and amber colored, you’ll start to notice swirls of a darker amber and the sugar will begin to smoke a bit.

Give it about 15-30 seconds to smoke (depending on how deep you want the flavor) then start pouring in the heavy cream, very slowly and stirring as you do. The caramel will bubble up (this is why you have a deep pot!) so be careful.

Once all the heavy cream is in, stir it and add the butter, vanilla bean and scrapings if using, and salt. Stir occasionally until the butter fully melts.

(If you start to see the butter sitting in an oily layer on top, get a whisk and whisk it vigorously).

Take the caramel off the heat and, if using the paste or extract, add the vanilla.

Let the caramel cool to room temperature then carefully lift out and discard the vanilla bean.