Preheat Oven and Prepare Pan: Preheat your oven to 350°F (180°C). Line an 8x8 inch baking pan with parchment paper, leaving some overhang for easy removal.
Mix Dry Ingredients: In a large bowl, add the flour and sugar and whisk until well combined.
Add Wet Ingredients: Make a well in the center of the dry ingredients. Add the melted butter and beaten egg. Mix until combined into a thick batter.
Transfer Batter: Spread the batter into the prepared pan, pressing it in firmly.
Bake: Bake for 20-25 minutes or until a toothpick inserted into the center comes out mostly clean with a few moist crumbs.
Cool and Serve: Allow the coconut slice to cool in the pan for 10 minutes, then use the parchment paper to lift it out onto a wire rack to cool completely before making the icing.
Coconut Icing
Sift: Sift the powdered sugar into a medium-sized mixing bowl to ensure no lumps remain. Whisk through the desiccated coconut.
Add Liquids: Pour in the melted butter and boiling water. Whisk until the mixture is smooth.
Spread Icing & Extra Coconut: Pour and spread the icing over the completely cooled base. Sprinkle the shredded coconut over the icing.
Set in Refrigerator: Place the slice into the refrigerator to set for 1-2 hours or until the icing is set.
Slice: Once set, cut the coconut slice into squares. Enjoy!
Notes
Room Temperature: Keep the coconut slice in an airtight container at room temperature for 1 week.
Freezing: For longer storage, wrap individual slices in plastic wrap and then aluminum foil or in freezer-safe bags. Freeze for up to 3 months. Thaw at room temperature before serving.