Grease several baking sheets or coat with nonstick spray.
In a large saucepan over medium-high heat, stir together the fresh and dried apples, apple jelly, cinnamon and nutmeg. Cook, stirring frequentlym until the jelly melts and the fresh apples are softened, about 5 minutes, be careful not to burn.
Let stand or refrigerate until cooled to room temperature.
In a medium bowl, thoroughly stir together the flour, baking soda, and salt and set aside.
In a large bowl, with electric mixer on medium speed, beat together the butter and brown sugar until well blended and fluffy. Add the egg yolk and beat until incorporated. Gently beat in half of the flour mixture. Add the cooled apple mixture and beat until well blended. Stir in the remaining flour mixture until evenly incorporated.
Let the dough stand for 5 minutes or until firmed up slightly. Using an 1/8 cup measure or coffee scoop, drop dough onto the baking sheets, spacing about 3" apart. With a greased hand, pat down the cookie tops until flat.
Bake the cookies, one sheet at a time, in the middle of the oven for 9-12 minutes or lightly tinged with brown all over and barefly firm when pressed in the centers. Reverse the sheet from back to front halfway through baking, to ensure even browning. Transfer the sheets to a wire rack and let cookies stand until the cookies firm up slightly 1-2 minutes.
Using a spatula, transfer the cookies to wire racks to cool completely.
FOR THE ICING: In a small bowl, stir together the powdered sugar, corn syrup, vanilla and enough drops of warm water to a thin icing.
Spoon the icing into a paper cone or small pastry bag fitted with a fine writing tip.Set the wire racks with cookies over wax paper to catch drips.
Drizzle the icing back and forth over the cookies to form thin, decorative lines. Let stand until the icing completely sets, about 30 minutes.
Store in an airtight container for up to 1 week or freeze for up to 2 months.