To a large bowl (that’s heat safe) set over simmering water, add the dark chocolate, oil, brown sugar, granulated sugar and ½ cup (170 g) of prune-flaxseed mixture. Make sure the water doesn’t boil or touch the bottom of the bowl. Stir frequently until the chocolate is melted and then pour the mixture back into the blender, add the vanilla, water and peppermint extract and blend on low until quite smooth, no more than 1 minute.
Stir in the sea salt, baking powder, baking soda until completely combined and then fold in the flour until the dough is mixed, but you still see streaks of flour. It will be very thick. Add the chocolate chips and fold until evenly mixed throughout the dough. The dough will appear slightly glossy and quite thick, this is perfect.
Portion 2 tablespoons (28 g) of dough into a ball and place on the cookie sheet, allowing about 2 inches (5 cm) between each dough ball. Prior to baking, gently press the dough balls down to form a disc (rather than a ball). Bake one sheet at a time in the center of the oven for 10 minutes. You want to slightly underbake these. Allow the cookies to cool on the sheet for 15 minutes then transfer to a wire rack. *When baking, allow more space between the cookies than shown in the photo below.