Acai berry can be bought in frozen form or in powder form. If you use a frozen acai pack, run it under warm water in the package until it is thawed and add it to a blender with your muffin mix to combine. Then just pour it into your muffin pan. If you’re using the powder, use ¼ cup of the powder per recipe. Acai makes an awesome replacement to blueberries and adds tons of antioxidants to your muffins too!