- Preheat oven to 375 degrees and spray the bottom of a 8 or 9 inch square baking pan with non-stick cooking spray. Open and drain the can of blueberries from inside the box of muffin mix. Set aside.
- In a bowl, mix together the muffin mix, water, oil, and egg just until combined. The batter will be lumpy.
- Gently fold in the lemon rind and blueberries into the batter. Pour batter into the prepared baking dish. Bake for 23-30 minutes until top starts to get golden and toothpick inserted in the center comes out clean. Allow to cool for 10 minutes.
- In the meantime, combine the powered sugar and lemon juice together to created a glaze. Drizzle the glaze over the coffee cake after it has cooled for the 10 minutes and serve.