Adjust the oven rack to the middle position and heat the oven to 350° F. Line 2 baking sheets with parchment paper and lightly spray the parchment paper with non-stick cooking spray (alternatively you can use silpat mats without spray)
Whisk together the cream of coconut, corn syrup, egg whites, vanilla and salt in a small bowl. Set aside.
Combine the unsweetened and sweetened coconut in a large bowl, toss together, breaking up any clumps with your fingertips. Pour the liquid ingredients into the coconut and mix with a rubber spatula until evenly moistened.
Drop heaping tablespoons of the batter onto the prepared sheets, spacing them about 1-inch apart. Form the cookies into loose haystacks or mounds, moistening your hands with water as necessary to prevent sticking (yes, this actually helps since the "batter" is pretty loose).
Bake at 350° F for 15 minutes or until the cookies are light golden brown, rotating the baking sheets halfway through. Cool cookies on the baking sheets until slightly set, about 2 minutes. Remove to a wire rack with a wide metal spatula.
While cookies are cooling, melt chocolate in a double boiler or makeshift double boiler (see tips for melting chocolate). Dip the bottoms of the cookies in the chocolate and place on a cookie sheet lined with wax paper or parchment paper. Place cookies in fridge for chocolate to set. Store in an airtight container.
Cream of coconut may be hard to find in your grocery store. I tried the baking section where the sweetened condensed milk is, the Asian section and the whole foods section. I finally found it near the Goya beans! You can also buy cream of coconut online. Storing coconut macaroons: Place cookies in an airtight container with parchment paper between layers. Store in the refrigerator for 1 week. Macaroons may also be kept at room temperature, but they won't keep their flavor and texture as long.Freezing coconut macaroons: Place cookies in an airtight container with parchment paper between layers. Store in the freezer for up to 3 months. Defrost in the refrigerator before serving.Suggested tools: