This delicious coconut candy is from Iran.
Butter a 12-by-17-inch baking sheet, and set aside. Place 1/2 cup desiccated coconut in an 8-inch-square baking pan; spread in an even layer.
Combine the sugar, cream of tartar, and the water in a small saucepan, and stir to combine. Bring to a boil over medium-high heat, brushing down the sides of the pan with a pastry brush dipped in water to prevent crystallization. Clip on a candy thermometer, and cook, without stirring, until the temperature reaches 240 degrees.
Pour the sugar mixture onto the prepared baking sheet in a constant, steady stream, holding the pan close to the surface; do not allow any stray drips to fall onto the baking sheet. Allow the poured syrup mixture to sit undisturbed until just warm to the touch on the surface.
Using a wide offset spatula, lift the sides of the jelled syrup, and fold over into the middle. Repeat this process, adding 1 1/2 cups coconut and the vanilla extract, until the mixture becomes slightly stiff and opaque white, about 3 minutes.
Quickly press into the coconut-lined pan; flatten into an even layer. Cover with the remaining 1/2 cup coconut, and press to adhere. Let sit 5 hours or overnight.
Invert the pan to unmold. Carefully cut the coconut sweetmeat into eight 1-inch strips using a serrated knife. Cut each strip diagonally to make diamonds. Store in an airtight container for up to 2 weeks.