Preheat the oven to 180℃, line a baking tray with baking paper and set aside.
In a mixing bowl add the water, oil and sugar - whisk until sugar is dissolved around 3-4 minutes.
Pour the melted cooled chocolate into the mixture and whisk again until smooth.
Add the flour, cocoa powder, baking powder, salt and whisk to combine, at this point you can switch to a rubber spatula.
Using a table spoon portion out the batter onto the baking tray and do not over crowd them as it will spread as they bake. I like leave 2-3 inches space between the cookies, you can bake them in batches if needed.
Bake for 9-10 minutes or until the top is crinkled and the edges are firm, the center might still be a little soft and that is fine as it will finish baking in the residual heat.
Allow them to cool on the baking tray for 3-5 minutes, hit them with sea salt flakes now. Using a metal spatula to transfer them to a wire rack to finish cooling.