Line a baking sheet with parchment paper or foil.
Microwave: Place chocolate in a bowl and microwave on high for 1 minutes. Stir until smooth and melted, heating in additional 10-second increments if necessary.
Stove: Place one inch of water into a wide saute pan and place on stove. Put chocolate in a heatproof bowl and set it directly in the water. Bring the water to a simmer then turn off the burner and allow the chocolate to melt, stirring occasionally.
Stir 1/3 cup of toasted coconut and salt into the chocolate.
Pour the chocolate mixture onto the baking sheet and spread out to a rectangle. Spread remaining 1/3 cup of toasted coconut over the top, pressing gently into the chocolate. Optional: sprinkle ¼ teaspoon of coarser sea salt on top. Place baking sheet into the refrigerator and chill for at least 60 minutes.
Break the bark carefully into chunks.