Preheat the oven to 400°F. Spray a 12-cup muffin tin with nonstick spray or line with paper liners.
In a large bowl, whisk together the flour, oats, sugar, baking powder and cinnamon.
In a small bowl, whisk together the milk, butter, syrup and egg; stir it into the dry ingredients and mix just until moistened. Fold in the apples.
Fill the prepared muffin cups ¾ full (this is easiest to do when you use an ice cream scoop). Top each with a pecan half. Bake for 18 to 20 minutes or until the muffins test done. Cool in the pan for 10 minutes before removing to a wire rack to cool completely.
ADD THE GLAZE:
In a small bowl, mix the powdered sugar with syrup and drizzle over the cooled muffins.