Preheat the oven to 350. Coat an 8x8-inch baking pan with a light layer of grease or line it with parchment paper to make lifting out the baked treat a breeze.

Melt the coconut oil and cocoa powder together in a microwave-safe bowl or over a double boiler. Keep stirring until the mixture turns smooth, then set it aside to cool down slightly.

In a mixing bowl, blend the melted coconut oil with the sugar until well mixed.

Add one egg at a time, making sure to whisk thoroughly after each one. If using flax eggs, add them all at once and mix thoroughly.

Stir in the vanilla extract.

In a separate bowl, combine the flour, baking powder, and salt, and give it a good whisk to blend everything evenly. Slowly add the dry ingredients to the wet mixture, gently folding until everything is blended.

Gently fold in the dark chocolate chunks, if using.

Carefully pour the batter into your prepared pan and spread it out evenly to cover the entire surface.

Bake for 25-30 minutes, or until a toothpick inserted in the center comes out with a few tiny, moist crumbs sticking to it.

Let the brownies cool in the pan for 15 minutes before slicing and serving.