Preheat the oven to 400°. Spray a 12-cup muffin pan with nonstick cooking spray or use cupcake liners.
In a large bowl, mix together the flour, oats, raisins, baking powder, and salt.
In a medium bowl, beat together the milk, brown sugar, apple juice concentrate, margarine, egg and vanilla
Add the wet ingredients to the flour mixture and stir just until blended.
Spoon the batter evenly into the prepared muffin pan and bake until the muffins are springy to the touch and lightly browned, and add a toothpick inserted in the center of a muffin comes out dry. 18-20 minutes. Turn the muffins out onto a rack to cool.