For Bottom Crust, in a large bowl beat butter and sugar with an electric mixer on medium-high speed until light and fluffy. Add vanilla and lemon zest; beat until just combined, scraping down sides of bowl and necessary. Add egg yolks; beat until combined. Add flour and salt; beat until dough just comes together. Using your hands, knead dough until flour is fully incorporated.
Coat a 9-inch fluted tart pan with removable bottom with nonstick cooking spray. Press dough into the bottom and sides of the pan. Cover with plastic wrap; freeze 20 minutes.
Preheat oven to 350°F. Bake crust, uncovered, 18 minutes or until edges of just start to brown and the bottom appears dry. Remove from oven. Cool on wire rack.
In a very large bowl toss together apples, pears, cake crumbs, cranberries. flour, brown sugar, and orange zest; set aside. In a small bowl whisk together instant pudding mix, cream, and orange juice for 1 minute or until well blended. Let stand 3 minutes until thickened. Stir pudding mixture into apple mixture. Mound filling into prepared crust*, leaving about 1/2 inch around the edge to tuck in pastry top.
Unfold puff pastry. On a lightly floured surface roll out pastry to a 12-inch square. Carefully drape pastry over filling. Tuck edges of pastry between filling and bottom crust; trim excess pastry. In a small bowl combine 1 egg and 1 Tbsp. water. Using a pastry brush, brush pastry with a egg mixture. Transfer pan to a foil-lined baking sheet. Bake 50 minutes or until top crust is golden brown. Remove from oven. Cool completely on a wire rack.
For Icing, whisk together powdered sugar and milk until smooth. Spoon half the icing over top of the pie; let stand 2 minutes. Spoon remaining icing over. Top with maraschino cherry, if desired.
If you place the filling in an 8-cup measuring cup, then invert it into the prepared crust, the mounding is done for you.