01 -
Turn your oven on to 175°C. Give the sides of a 25 cm cast iron skillet the lightest spritz of cooking spray you can manage.
02 -
Drop your butter into the skillet and let it melt on medium until you see bubbles. Toss in that brown sugar and keep whisking for 2 to 3 minutes. When it starts bubbling and looks thick, splash in the vanilla and whisk it good.
03 -
Take the skillet off the burner and let it hang out for a minute. Shake the coconut all over the sticky topping. Don't worry about perfection. Put the skillet aside.
04 -
Grab a medium bowl and toss in cocoa, flour, salt, and baking soda. Give it a good whisk, then just set it off to the side.
05 -
Use your mixer bowl and beat together the sugar with your room-temp butter on medium-high. Let it get nice and fluffy—it shouldn't take more than 2 minutes.
06 -
Lower the mixer speed. Crack in the eggs one by one, scraping down the bowl each time. After that, crank up the speed. Let it whip for a minute till it looks extra fluffy. Pour in the vanilla and stir.
07 -
Turn the speed down low. Add half the flour blend, pour in half the milk, then do the rest. Stop once you barely see any flour left; some dry bits are totally fine.
08 -
Scrape around the bowl. Turn the mixer to high for just 8 seconds. That's it—don't beat it too long.
09 -
Carefully drape the batter on top of the coconut layer. Use your offset spatula to smooth things out. Pop it in the oven for 35-40 minutes, or until you stick a toothpick in the middle and it comes out clean.
10 -
Put the skillet on a wire rack to cool for 5 minutes. With oven mitts, quickly flip it onto a plate. Let it sit for 20 minutes more before you cut in—enjoy it warm or at room temperature.