Preheat oven to 350° Fahrenheit. Adjust oven racks as needed so pan will sit in center of oven. Line 8x8 metal pan with parchment paper, leaving excess parchment paper out on each side to help with removing brownies later. Set pan aside.

Place coconut oil in microwave-safe bowl. Place bowl in microwave and microwave oil 30 seconds, pausing to stir coconut oil every 10 seconds until melted.

Once coconut oil is melted, add 1 cup chocolate chips to bowl, then gently stir chocolate chips into melted coconut oil. Stir constantly until chocolate is completely melted and ingredients are fully combined. Set bowl aside.

Add coconut sugar and 2 eggs to large bowl (or stand mixer bowl). Use hand mixer (or stand mixer) on medium-high or high speed to beat ingredients 2 to 3 minutes or until mixture is just light and fluffy. Be careful not to over-mix.

Set mixer aside. Pour melted chocolate into egg & sugar mixture. Gently stir until chocolate is fully incorporated.

Add vanilla extract, cocoa powder, oat flour, rolled oats, brewer's yeast, ground flaxseed, and salt to bowl. Mix ingredients together by hand until just combined. Do not over-mix.

When ingredients are just combined, add remaining ½ cup chocolate chips to bowl. Gently fold chocolate chips into brownie batter until just incorporated.

Transfer brownie batter to prepared baking dish. Be sure to spread batter evenly into all 4 corners of baking pan, ensuring mixture is distributed evenly.

Place baking pan in preheated oven. Bake brownies 25 minutes, then check for doneness. Center of brownies should be just set, and toothpick or knife inserted into center should come out mostly clean, covered in very few crumbs. If brownies are not ready after 25 minutes, return pan to oven and bake 5 minutes more, then check doneness again. Note: if in doubt, remove brownies from oven. At this point, slightly underdone is better than slightly overdone.

When brownies are ready, carefully remove pan from oven and set aside to cool. Allow brownies to cool, undisturbed, 20 minutes. Brownies will continue baking slightly during cooling.

Once brownies reach room temperature, carefully use overhanging parchment paper to lift brownies out of pan. Use sharp knife to slice brownies into at least 9 squares, cleaning knife between each cut for clean edges if desired. Enjoy as desired.