Preheat your oven to 350°F / 175°C.
Grease an 8-inch or 9-inch square baking pan.
In a bowl using an electric mixer, cream the softened butter with ¼ cup of the sugar and the salt until light and fluffy.
Stir in 1 cup (240 ml) of the flour and the lime zest. The mixture will be dry and crumbly.
Press the crust mixture firmly and evenly into the bottom of your prepared pan.
Bake for 20 minutes, until the edges are just beginning to turn golden.
Remove from the oven and let it cool slightly while you prepare the filling.
In a separate bowl, beat the eggs, fresh lime juice, and the remaining 1½ cups of sugar until the mixture is light, thick, and pale in color.
Mix in the remaining 3 tablespoons (45 ml / 1.5 fl oz) of flour and the baking soda until just combined.
Pour this luscious filling over the slightly cooled crust.
Sprinkle the shredded coconut evenly over the top.
Bake for 25 to 30 minutes, or until the edges are firm but the center is still slightly soft and jiggly. Rotate the pan halfway through if it's baking unevenly.
Let the bars cool completely in the pan on a wire rack before cutting into squares. Store any leftovers in a covered container in the refrigerator for up to 2 days.
