Preheat the oven to 325°F (162°C) and line an 8 x 8 dish with parchment paper. (Tip - use a little spray oil on the pan before lining with parchment to hold it in place.)
In a small bowl or measuring container, mix 4 tbsp chickpea flour with 2 tbsp water. Stir until you have a thick paste, then add 2 additional tbsp of water and stir again. Set aside for at least 5 minutes.
In a large mixing bowl, combine 1 cup white sugar, 3/4 cup flour, 2/3 cup cocoa powder, 1/2 cup powdered sugar, 1/3 cup brown sugar, 1/3 cup vegan chocolate chips, and 3/4 teaspoon salt. (Sift the cocoa powder and powdered sugar through a mesh strainer if they are lumpy.)
After your chickpea egg has sat for at least 5 minutes add 1/3 cup of oil, 2 tablespoons of vegan milk, and 1 teaspoon of vanilla to it and stir well.
Pour the wet ingredients into the dry ingredients and fold together with a rubber spatula until well combined. (It will be a very thick batter. If your batter has dry spots after 2 minutes of stirring, sprinkle with 1-2 teaspoons of water until a thick consistent dough is formed.
Put your batter into the prepared pan and press with the spatula so that it's even and flat and top with an additional 1/3 cup chocolate chips if desired.
Bake at 325° F (162°C) for 40-45 minutes until a toothpick inserted in the center comes out mostly clean. (The melted chocolate chips will stick to the toothpick.) Cool completely before cutting with a large knife.
Notes
Follow the recipe exactly. Brownies can be fussy and slight changes to the ingredients can change the outcome significantly.
Spoon measure the flour. Don't scoop the flour out of the bag with the measuring cup or it will pack down and you will be using too much.
Allow your brownies to cool for at least 2 hours before cutting otherwise they will be too soft and gooey to cut into nice squares.
If you want your brownies to come out in nice neat squares, I highly recommend lining the bottom of the pan with parchment paper before baking.
They taste great with a little coarse salt sprinkled on top of them.