In a pot over low heat, combine the granulated sugar, light brown sugar, salt, evaporated milk or half-and-half, and butter.
Bring the mixture up to 235°F (use a thermometer) before turning the heat off.
Cool for 5 minutes in the pan.
Add the 2 cups of whole pecan halves (not chopped) and stir to combine.
Quickly spoon the mixture onto silicone sheets and cool completely to room temperature.
Do not eat until completely cool and hard, as hot sugar can cause burns.
Store at room temperature in a sealed container so it doesn't go stale.
