Peel and core apples and cut into 1/4-inch wedges. In a skillet heat butter over moderately high heat until foam subsides and saute apples until a rich golden, 6 to 8 minutes. Reduce heat to low. Carefully stir in syrup, walnuts, cinnamon, and lemon juice and cook until apples are tender throughout but not mushy and liquid is reduced to a syrup-like consistency. Remove skillet from heat and stir in Grand Marnier. Cook filling over low heat 1 minute to blend flavors and keep warm. Filling may be made 1 day ahead and chilled, covered. Reheat filling before proceeding. Preheat oven to 250°F. Put 2 1/2 tablespoons warm apple filling in center of each pancake and roll up pancakes tightly to enclose filling. In a baking pan keep filled pancakes warm in oven. In a bowl with a whisk or an electric mixer beat cream with confectioners` sugar and cinnamon until it holds soft peaks and fold in creme fraiche. Put 2 filled pancakes on each of 6 dessert plates. Top pancakes with some cinnamon cream and drizzle with fudge sauce.