Preheat the oven to 375°F/190°C.
Core the apples, cutting to within a 1/2 in. of the bottom, but leaving the bottom intact. Cut a slice the thickness of a 1/2 in. off the stem end and set aside.
In a small sauce pan over medium-high heat, combine 6 Tbsp. brown sugar, 3 Tbsp. butter, 3/4 c. water, 1/2 tsp. cinnamon and the lemon zest. Bring to a boil, stirring to dissolve the sugar. Remove the syrup from the heat and set aside.
In a bowl, mix together the walnuts, dried apples, raisins, apricots, the remaining 2 Tbsp. brown sugar, 1/4 tsp. cinnamon, 2 Tbsp. melted butter and 3/4 of the crushed amaretto cookies. Reserve the remaining crushed amaretto cookies.
Fill the apples with the mixture, distributing evenly. Place the reserved apple tops on top of the filling.
Place the apples in a 11-in. chef's skillet and pour the syrup over them. Cover with foil, place in the oven and cook until the apples are tender, about 30 minutes.
Remove the foil and baste with the pan juices. Recover with foil and continue to cook until the apples are tender, 10 - 15 minutes, depending upon the variety of apples. When the apples are done, remove the foil and spoon some of the syrup over the top.
To serve, spoon the mascarpone into the hole on the top of each hot baked apple, distributing evenly. Sprinkle with the reserved crushed amaretto cookies. Drizzle the syrup from the pan around the edges of each dish before serving.