Preheat oven to 350°. Spray a 12-cup muffin pan with baking spray with flour.
In a large bowl, whisk together 2 cups flour, ½ cup sugar, baking powder, and salt.
In a medium bowl, whisk together lemon curd, coconut milk, oil, eggs, and zest. Add coconut milk mixture to flour mixture, whisking until combined. Stir in 1 cup coconut. Divide batter among prepared muffin cups.
In a small bowl, stir together remaining ½ cup flour, remaining ½ cup sugar, and remaining ½ cup coconut. Add melted butter, and stir until mixture is crumbly. Sprinkle topping over batter.
Bake until a wooden pick inserted in center comes out clean, 20 to 23 minutes. Let cool completely on a wire rack. Sprinkle with zest, if desired.
Recipe by Taste of the South at https://tasteofthesouthmagazine.com/coconut-lemon-muffins/