In a standing mixer, combine all the dry ingredients: flour, sugar, cocoa powder, baking powder, baking soda, and salt.
Turn the mixer on low and pour the hot water and vegetable oil in. Turn off the mixer after you have poured both in.
Add the eggs and stir until just combined.
Turn the mixer on low again and pour the buttermilk in. Add the vanilla extract in after.
Continue mixing until the batter is smooth.
Pour the batter evenly into 20 large cupcake molds lined with cupcake liners
Bake for 20 minutes.
Remove the cake and allow to cool in the pan. Once cooled, remove from the pan.
Caramel Sauce
In a medium sauce pan add the sugar and water, turn the heat on to medium-high and whisk until fully combined
Continue whisking as the sugar caramelizes. It takes just under 10 minutes; the sugar will thicken as it cooks and sometimes clumps up, but don't worry! Just be careful not to burn the sugar.
When caramelized, you can tell because the sugar is golden brown. Add 1 tablespoon of butter at a time as you whisk.
Once the butter is all added, slowly pour half and half of the cream into the bowl while whisking. Be careful; the steam can burn you if you pour it too quickly.
Now add the salt and vanilla. Stir until combined. Take off the heat; if you still feel a few sugar clumps in your mixture, pour the sauce through a sieve to catch them, leaving you with perfectly smooth caramel sauce.
Frosting
Add the butter, caramel, and powdered sugar in a mixing bowl or standing mixer. Mix until combined.
Turn the mixer up to medium-high and whip for 2 minutes.
Gooey Coconut
In a small bowl, combine the caramel sauce and coconut and stir until all the coconut is covered.
Assemble
Take the cooled cupcakes and top each with a small spoonful of leftover caramel sauce.
Spread the caramel frosting on each caramel topped cupcake