Preheat oven to 350 degrees F. Spray an 8-inch square baking dish with combine topping ingredients; mix with a fork until crumbly. Set aside.
For the filling, combine the pears, cranberries, and lemon juice in a large bowl. Add the ginger, sugar, and flour and toss to combine.
Transfer the pear mixture to the prepared baking dish and top with crumb mixture. Bake for 35 to 45 minutes until the filling is bubbly and the topping is a golden brown. Cool for at least 15 minutes before serving, or cool completely and serve later.