Magic because they looked so weird going into the oven, but they turned out fine--actually one of my better blueberry efforts. Blueberry muffins can come out strangely green if the berries react with the other ingredients; these started out frighteningly purple, but baked into just a nice brownness.
I don't have the exact recipe, but this is what I did: combined all the wet ingredients for basic muffin batter, plus some frozen blueberries and a spoonful of strawberry jam, in the blender. I combined the dry ingredients in a bowl, stirred in more whole blueberries, and then mixed in what looked like the purple smoothie from the blender. It looked seriously yucky at that point, but since I had gone that far, I carried on, spooned the batter into muffin papers, and baked them. Success!
Two other things: they peel out of the papers better if you let them cool first. Most muffins do, but fruity ones especially. And store any leftovers in the fridge.