Prepare the Water Bath: Fill a medium saucepan with about 2 inches of water and warm over medium heat. Place a large glass or stainless-steel mixing bowl over the saucepan to create a water bath, making sure the bottom of the bowl does not touch the water. Add the chocolate chips (and vanilla, if using) to the bowl.

Melt the Chocolate: When small bubbles form along the bottom of the pan (but the water is not simmering), reduce the heat to medium-low to maintain a temperature around 180ºF. Stir the chocolate continuously as it melts, pressing the chips against the sides of the warm bowl and scraping down the sides with a spatula as needed. Continue stirring until fully melted and smooth, about 10 minutes.

Coat the Pecans: Fold the pecans into the melted chocolate until they are thoroughly and evenly coated.

Chill to Set: Spread the chocolate covered pecans in an even layer on a parchment-lined rimmed baking sheet and sprinkle with the salt. Transfer the baking sheet to the refrigerator and chill for 45 minutes, or until the chocolate is fully set. For a more polished look, you can dip each pecan halfway in chocolate—but it takes considerably more time and requires an additional baking sheet so they don’t touch.

Break and Store: Break the pecans into small clusters. Store in an airtight container at room temperature for up to 1 month, or freeze for up to 3 months.