Preheat your oven to 350 degrees Fahrenheit.
Whisk together the flour, baking powder, baking soda, salt, cinnamon, and nutmeg in a medium mixing bowl.
Toss the shredded apples with lemon juice in a separate bowl to prevent oxidation.
Cream the butter and brown sugar in a stand mixer until the mixture looks pale and fluffy.
Add the egg and vanilla extract, mixing until fully incorporated.
Slowly add half the flour mixture, then the apple juice concentrate, and finish with the remaining flour.
Fold in the shredded apples including their juices.
Scoop dough into 1.5-inch balls and place on a lined baking sheet.
Bake for 12 minutes.
Prepare the glaze by melting butter and brown sugar together, whisking in milk, then drizzle over cooled cookies and top with toasted pecans.