Preheat your oven to 350°F and lightly grease an 8-inch square baking dish.
In a large mixing bowl, whisk together the sugar, flour, baking soda, and salt.
Add in the egg, coconut milk, oil, and vanilla. Stir until smooth and well combined. No need to overthink it.
Pour the batter into your prepared pan. If you’re using shredded coconut, sprinkle it over the top like edible confetti.
Bake for 28 to 33 minutes, or until the center is set and the top has a slight golden color. It should smell like something you want to crawl into.
Let the cake cool in the pan for at least 15 minutes. It’s great warm, but it firms up a little more as it cools.