If you're using boxed blueberry muffin mix, this frozen food aisle staple is the add-in you don't need to think twice about.

These healthy purple muffins are packed with good stuff. They're tasty, too, so perfect for both adults and kids. Preheat the oven to 180C/350F/Gas 4. Line a 6-hole muffin tray with paper cases.

Preheat the oven to 425℉. Line a 12-cup standard muffin pan with paper liners, or grease with nonstick cooking spray. In a large bowl, whisk together the all-purpose and whole wheat flours.