In the bowl of a stand mixer fitted with the paddle attachment, crumble the cooked brownies into about 1-inch-sized pieces.
Beat on medium-low speed for 1 to 2 minutes, until the brownies ball up and form a mass.
With a 1 tablespoon-sized triggered cookie scoop or tablespoon measuring spoon, scoop the brownie mixture and roll with your hands to form tight, 1-inch balls.
In a medium, heat-proof mixing bowl (that fits over a double-boiler), place the chocolate chips.
Fill the double-boiler with 1 inch of water. Place it over medium-high heat and bring to a simmer. Reduce the heat to medium-low and place the bowl with the chocolate over top. (Be sure that the base of the bowl does not touch the water.)
Let the chocolate melt for 4 to 5 minutes, then stir until it is melted. Remove from the heat.
Place 2 to 3 truffles at a time in the melted chocolate. Spoon the chocolate from the bowl over the truffles to coat completely. Use a toothpick to remove each truffle from the chocolate, letting any excess drizzle off. Transfer to a parchment-lined baking sheet. Repeat with all of the remaining truffles.
While the chocolate is still wet and glossy, sprinkle with sprinkles or flaky sea salt if you like.
Notes
Fudgy brownies work best for this recipe. They are stickier, so the crumbled brownie will be easier to roll into balls.
Don’t use the crispy edges. If your brownies bake with hard, crispy edges, don’t add them to the stand mixer. Just trim off the hard edges and crumble the rest into the mixing bowl. Dry or crumbly bits will not hold together well.
Use chocolate bars instead of chips. You can use 12 ounces of semi-sweet, bittersweet, or dark chocolate bars in place of the chocolate chips. Bars usually melt more smoothly and set firmer, so there is no need to add any coconut oil.
Freeze the brownie balls before dipping. To make the brownie balls easier to handle and dip, you can freeze them on a parchment paper-lined baking sheet for 20 to 30 minutes so they firm up before coating them in chocolate.