Place sugar in a medium skillet over medium-high heat. Stirring constantly, cook until the sugar melts, about 5 minutes. The sugar will seize during this process, but that is okay! Just keep stirring.

Once the sugar has melted, continue to cook until it becomes a dark brown, foams and smokes, about 1 minute.

Immediately and carefully remove from heat.

Stirring constantly, pour in the hot water. The sugar will splatter a lot, so be careful.

Once the water in fully incorporated, return to medium-high heat and cook until the syrup thickens slightly and most of the bubbles are around the size of a dime, about 2 minutes.

Allow to cool completely before use.