Preheat oven to 350 degrees F. Spray an 8x8 inch square baking pan with non-stick cooking spray. Line the bottom of the pan with parchment paper and drape the parchment over two opposite sides of the pan. This will provide a handle to pull out the brownies. Then spray the parchment with non-stick cooking spray.
In a large mixing bowl, add in the butter, sugar, eggs and vanilla. Using a hand mixer, beat for 1 to 2 minutes until the mixture turns pale and becomes thick and fluffy.
Add in the baking powder, hot cocoa envelopes and flour. Mix with the hand mixer on low until incorporated. Scrape down sides and give a quick mix to incorporate.
Stir in ½ cup of mallow bits into the batter.
Spread the batter into the prepared pan. Make sure to spread to all of the edges and corners.
Sprinkle the remaining 2 tablespoons of tiny mallow bits on top of the brownies.
Place into the oven and bake for 35 minutes or until done. Place a toothpick into the center of the brownies and if it comes out clean or with moist crumbs, it's done. If there's still batter, let bake a little longer.
Remove from the oven and let cool.
Cut into squares and serve!
Notes
The recipe initially called for 4 hot cocoa packets, but I find that 5 gives it a more dense brownie texture and a little extra hot cocoa flavor. 4 packets still work perfectly too.