Preheat the oven to 375°F. Butter four 1-cup individual dessert dishes or ramekins and place on a large baking sheet lined with parchment paper for easy cleanup (optional). Set aside.
For fruit: Peel, core, and slice the pears, cutting most of the slices in half or coarse chunks. Place in a large bowl and stir in the cranberry sauce, sugar, lemon juice, and flour. Divide the fruit evenly among the dessert dishes.
For topping: Mix the flour, oats, brown sugar, cinnamon, and salt in a large bowl. Add the butter and rub it into the dry mixture with your fingers until you have uniform, buttery crumbs. Divide the mixture evenly between the cups, patting it down lightly on top of the fruit. Place the baking sheet with the dishes on the center oven rack and bake for 30 to 35 minutes, until the topping is golden brown and the fruit is bubbling. Cool on a rack for at least 15 minutes before serving.