Whisk flour and salt. Using your fingers, rub cream cheese and 8 Tbsp. butter into flour mixture until butter is almost incorporated and pea-size lumps form. Add 1 Tbsp. each cold water and maple syrup; mix with a fork until a rough dough forms. Gather dough into a 1-inch-thick disk and wrap in plastic wrap. Refrigerate for at least 20 minutes.
Preheat oven to 400ºF with a rack in middle. Line a rimmed baking sheet with parchment. Cut another piece of parchment to fit a 10-inch skillet. Halve, core and slice pears 1/8 inch thick; in a bowl, toss with lemon juice, cinnamon and nutmeg.
In skillet, melt remaining 2 tsp. butter over medium-low heat. Add pear mixture. Cover surface of pears with parchment round and cook, stirring occasionally, until softened, about 5 minutes. Remove parchment and stir in cranberries and remaining 2 Tbsp. maple syrup. Cook until liquid is reduced to a glaze, about 2 minutes longer. Remove from heat and let cool slightly in skillet.
On a well-floured surface, roll out dough into a 13-inch round. Transfer to prepared sheet and brush top with egg. Using a slotted spoon, mound pears in center, leaving a 3-inch border. Discard juices. Fold pastry edges up and over filling, pleating dough as you go and leaving center exposed. Brush all over with egg; sprinkle with sugar, if desired. Bake until dough is golden brown on top and bottom and pears are tender, about 40 minutes. Let cool completely in pan on a wire rack. Cut into wedges and serve; refrigerate leftovers.