Line a big baking sheet with parchment and set it next to the stove. Keep a small bowl of cold water and a heatproof spoon close by.

Pour the sugar and cream into a medium heavy-bottomed pot. Stir gently until every bit of sugar is wet and it looks like thick cream.

Set it over medium heat and stir often until it starts to simmer steadily.

Once it's simmering, stop stirring much. Just swirl the pan now and then so sugar crystals don't form on the sides.

Let it bubble at a steady simmer to a low boil for 8 to 12 minutes. Adjust the heat as needed. It's ready when it thickens, turns deep golden caramel, and the bubbles get slow and heavy.

Test it: drop a little spoonful into the cold water. If it makes a soft ball that holds together when you press it, you're done. If it melts away, cook 1 to 2 minutes more and test again. With a candy thermometer, you want 235°F to 240°F.

Pull the pot off the heat right away and stir in the pecans until they're coated and shiny.

Drop heaping tablespoons onto the baking sheet, spaced a little apart, with a few pecan halves in each one.

Leave them at room temperature for 30 to 45 minutes, until firm with crisp edges and slightly glossy centers. Then peel them off the parchment.