In a large mixing bowl, combine the graham cracker crumbs, shredded coconut, melted butter, and sugar. Mix until well combined and slightly crumbly.
Press the crumb mixture firmly into the bottom of an 8x8-inch baking dish to form an even layer. Bake in the preheated oven for about 10 minutes or until lightly golden. Remove from the oven and set aside to cool slightly.
In a separate mixing bowl, whisk together the eggs until frothy. Add the sweetened condensed milk, fresh key lime juice, and lime zest. Mix well until the mixture is smooth and combined.
Pour the filling over the cooled crust, spreading it evenly. Bake for an additional 15-20 minutes, or until the filling is set but still slightly wobbly in the center.
Once baked, remove the dish from the oven and let it cool to room temperature. Then transfer to the refrigerator and chill for at least 2 hours or until firm.
When ready to serve, cut into bars and top with whipped cream if desired. Garnish with lime slices and extra zest for a pop of color and flavor.
Notes
Arrange the bars on a platter with lime slices and whipped cream for presentation.