Before you start making your brownies, add the 3 tablespoons of ground flaxseeds to a bowl and then pour over the ½ cup (120ml) hot water from the kettle. Leave it to sit while you prepare your other ingredients.
Preheat the oven to 350°F (180°C) and spray a 9x9 square baking dish* with non-stick spray and line it with parchment paper so that there is overhang on either side. Set aside.
Sift the all purpose flour and cocoa powder into a mixing bowl and add the baking powder and salt. Mix together.
Add the vegan butter and ½ cup chocolate chips to a microwave safe bowl. Microwave in 30-second intervals, bringing it out to stir every 30-seconds until melted.
Now add the flax eggs, white granulated sugar and vanilla extract to the melted vegan butter and chocolate and whisk it in with a hand whisk.
Pour this out over your dry ingredients in the mixing bowl and mix into a thick brownie batter.
Add the cup of chocolate chips and mix in.
Transfer the brownie mix to your prepared 9x9 square baking dish and smooth down.
Add a few more chocolate chips directly to the top of the brownies.
Place into the oven and bake for 35-40 minutes.
The brownies are done when they are dry and shiny on top and a toothpick inserted into the center of the brownies comes out with moist crumbs (or melted chocolate) but not wet batter.
Let the brownies cool and firm up for 15 minutes in the pan before using the parchment paper overhang to remove them from the pan and place onto a wooden board. Let them cool completely before slicing.