Preheat oven to 400F. Spray a 24-cup mini muffin tray with non stick cooking spray or line with paper liners.
Beat together egg, oil, yogurt and vanilla.
Stir in cinnamon and apple.
Add muffin mix (or pre-mixed dry ingredients listed above) and stir until just evenly moistened. (Batter is thick)
Spoon batter into about 16 prepared muffin tins. Bake until golden brown and toothpick comes out clean (about 13 minutes, or a little less). Let muffins cool in the pan for 5 minutes then transfer to a wire rack to finish cooling.
Refrigerate in airtight container for up to 3 days, or seal in a ziploc freezer bag for up to 3 months.
Recipe Credit to Kim Laidlaw - from her book Baby & Toddler On the Go