1 pound grated fresh or unsweetened shredded coconut
2 3/4 cups sugar
1 can (14 ounces) sweetened condensed milk
1 can (12 ounces) evaporated milk
Coat a 13-by-18-inch rimmed baking sheet with cooking spray. Stir together coconut, sugar, condensed milk, and evaporated milk in a large saucepan. Cook over medium-low heat, stirring constantly, until thickened, about 30 minutes.
Pour coconut mixture onto prepared sheet. Spread to 1/2 inch thick using an offset spatula; shape into a 12-by-13-inch rectangle. Let cool completely on sheet on a wire rack. Cut into 1 1/2-by-2-inch bars. Store between layers of parchment in airtight containers at room temperature up to 1 week.