In a bowl, prepare the brownie mix according to the box directions using the oil, eggs, and water listed. Stir just until combined so the brownies stay fudgy, not cakey.

Pour the batter into the prepared pan and spread it into an even layer. Bake according to the box directions for an 8x8 or 9x9 pan. When a toothpick inserted near the center comes out with a few moist crumbs (but not raw batter), they are done.

Place the pan on a cooling rack and let the brownies cool completely. This is important so the ganache sets properly.

Make the ganache: Add the chocolate chips and heavy cream to a microwave-safe bowl.

Microwave in 30-second increments, stirring in between. I usually only have to microwave mine for a minute total. Then, keep stirring until all of the chocolate is dissolved into the cream and everything is smooth (it does take quite a bit of stirring!).

Let the ganache sit at room temperature for 5-10 minutes, stirring every few minutes, until it has thickened to a spreadable consistency. You want it a little thicker than warm fudge sauce but still soft enough to glide over the brownies.

Once the ganache and brownies are fully cooled, pour the thickened ganache over the top of the brownies. Use an offset spatula or the back of a spoon to spread it into an even layer, all the way to the corners.

Immediately add your 4th of July sprinkles on top so they stick to the soft ganache. I like to go a little heavy with sprinkles for a really festive 4th of July desserts look.

Let the pan sit at room temperature for 30 to 60 minutes so the ganache firms up. If you want extra clean cuts or you are in a hurry, chill the pan in the fridge for 15 to 30 minutes until the top is set but not rock hard.

If you used parchment, lift the entire slab of brownies out of the pan onto a cutting board. Use a sharp knife to cut into squares or rectangles. Wipe the knife clean between cuts for picture perfect edges.

Serve at room temperature for the softest, fudgiest texture.