Open both cans of coconut milk into a large bowl and whisk hard for about 30 seconds, until the firm white cap and the thin layer underneath have combined into one uniform white liquid with no lumps. If the cap is very solid, warm the cans briefly in a pan of hot water first. This step is the difference between a smooth pop and one that is greasy on top and icy at the bottom.

Whisk in the sweetened condensed milk, the lime zest, the cayenne and the salt until there is no streaking anywhere in the bowl.

Pour the lime juice in a thin stream while whisking, rather than tipping it in all at once. Taste it and adjust the cayenne now, remembering that freezing mutes heat, so it should taste slightly more aggressive than you want the finished popsicle to be.

Divide the mixture between the cavities of a 10-cavity mold, leaving about a quarter of an inch of headroom at the top for expansion. Freeze for 1 hour, then push the sticks in while the mixture is slushy so they stand up straight and stay centered.

Freeze for 4 hours more, until the surface no longer gives at all under a fingertip. Run warm water, not hot, over the outside of the mold for 20 to 30 seconds, then pull each pop straight up with a gentle twist. If one resists, return it to the freezer for 10 minutes rather than pulling harder. Wrap any you are not eating in parchment and bag them.