IN THE MICROWAVE: pour the mix into a microwave-safe bowl and microwave for three 45 second increments (2 minutes 15 seconds total), mixing well between each increment. Use a silicone spatula to scrape down the edges while mixing.
IN THE OVEN: preheat your oven to 350 degrees and line a cookie sheet with parchment paper or a silicone baking mat. Pour the brownie mixture evenly throughout the cookie sheet. Bake for 8 minutes, stirring once after 4 minutes.
Once you have heated the brownie mix, I recommend sifting it to remove any clumps that formed while heating. Mixing well with a whisk or fork will help break up the clumps too.
Allow the mix to cool completely before making the brownie batter dip.