Preheat the oven to 350F.

In a small bowl, combine the ground flaxseed and water and mix to combine. Set aside to thicken.

In a large bowl, whisk together the sugar, cocoa powder, flour, salt, and baking powder.

Add in the melted butter, vanilla, and thickened flaxseed mixture. Mix until brownie batter comes together - it will be thick!

Line an 8x8 baking dish with parchment (VERY important, as these brownies like to stick!), and pour in the prepared brownie mix.

Smooth out with a spatula, and bake for 35 minutes, until brownie appears dry on top, and a toothpick inserted in the center comes out with just a few crumbs.

Let brownie cool to room temperature, then make the glaze. Combine the vegan chocolate chips and milk in a microwave safe bowl, and heat in 15 second increments until smooth and creamy. You may have to add a little more milk if it's too thick. It should be easy to pour!

Pour chocolate glaze all over the brownie, and sprinkle the rainbow chip sprinkles on top.

Place cosmic brownies in the fridge to help the glaze set. After it has solidified, you can store brownies at room temperature or in the fridge for a fudgier texture (my fav!).