Heat the oven to 350°F. Line two baking sheets with parchment paper. In a large bowl, whisk together the flour, baking powder, baking soda, and salt.
In another bowl, whisk together the coconut oil, tahini, water, and vanilla until smooth. Add the sugar and whisk until combined.
Stir in the dry ingredients until just combined then stir in the chocolate.
Portion the dough into 3 tablespoon balls. If the cookie dough seems soft, refrigerate for 10 minutes.
Bake, one pan at at a time for 12 minutes, until the edges have set but the centers are gooey. Cool on the pan on a wire rack for 20 minutes, or until the edges and bottoms are firm to the touch. Enjoy warm or at room temp. Cookies will keep in an airtight container at room temp for up to 3 days.