Preheat oven to 400 degrees F.Cream 1/2 cup butter and sugar together in a large mixing bowl until light in color, about 1-2 minutes.
Add egg and 1/4 cup milk; stir to combine.
Add remaining dry ingredients (except apple) and stir just until combined. Gently fold in the apples. Drop by heaping tablespoons onto a greased baking sheet.
Bake at 400 for about 10-12 min or until tops don't look wet anymore.To make the glaze, whisk together 1 tablespoon melted butter, 1 cup powdered sugar, 1/4 tsp maple flavoring, and 3 tablespoons milk in a small bowl. When the cookies have cooled for a few minutes, drizzle each cookie with glaze.