Instructions for 1000 Watt Microwave.
Place all of the ingredients into a deep microwave safe bowl, reserving the vanilla until the end of cooking. The bowl should be deep enough to allow the mixture to boil, without boiling over.
Cook in the microwave on high for 6 1/2 minutes, stopping to stir halfway through. The mixture will boil, so handle with care to avoid burning.
After 6 1/2 minutes, stop and stir coating all of the pecans. The caramel should be thickened and beginning to form along the sides of the bowl. If the caramel is still runny, it needs to cook a bit longer. Microwave in additional 1 minute increments, if needed.
Allow to cool on the counter for 15 seconds then mix in vanilla.
Use a teaspoon, tablespoon or small cookie scoop to drop in clusters onto buttered wax paper or a silicone baking mat.
Immediately sprinkle the tops with sea salt, if desired. Allow to cool and set.