Add the coconut milk, honey, coconut palm sugar, Duck Fat, and ½ teaspoon sea salt to a medium saucepan (a 6-8” pan is recommended for more accurate temperature readings).
Place over medium heat and stir occasionally until the coconut palm sugar has dissolved. Turn the heat to medium-low, insert a candy thermometer, and cook undisturbed until it reaches 280F. The mixture will bubble and spit a bit. If the volume begins to bubble toward the top rim of the saucepan, turn the heat down slightly. Remove the caramel from the heat and carefully whisk in the vanilla extract until smooth.
Pour the duck fat caramel out into a greased bread loaf pan (or other of similar size/shape). Place in the refrigerator until fully cooled.
Remove from the fridge and invert the pan to remove the sheet of caramel. Sprinkle with coarse flake salt, as desired. Use a knife dipped into warm water to quickly cut into shapes. Wrap in wax paper or parchment and store in the refrigerator for up to a month.