Line an 8×8″ pan with parchment paper. Run a stick of butter over the top to prevent the caramels from sticking.
Melt the butter in a large 8-cup microwave-safe bowl. Add the sugar, corn syrup and sweetened condensed milk and stir until smooth. Place in the microwave and cook for six minutes, stirring half way in between.
To test if the caramel is ready, place a spoon into the caramel and then into a cup of cold ice water. If it resembles a soft ball (the texture you’d want your caramels to be), then it’s ready. If it’s still too soft, cook for an additional 30 seconds to 1 minute. You don’t want to overcook or they will be too hard. Stir in vanilla and a pinch of sea salt. Add pecans if desired.
Pour caramel into prepared pans and allow to set. You may place in the refrigerator for 20 minutes to cool them quicker.
Cut with a plastic knife and then wrap in wax paper to prevent the caramels from sticking. Enjoy! :)