Preheat oven to 350°F/180°C. Grease a 1.5 QT baking dish and set aside.
In a large bowl, combine cut pears, sugar, citric acid, and flour. Stir until pears are fully coated. Pour into baking dish.
In the same bowl, add in flour, oats, sugar, salt, oil, and water. Mix with a wooden spoon. The topping should be wet but still crumbly. Spread topping evenly over pears.
Transfer baking dish to oven and bake for 45-60 minutes or until topping has become crispy.
Remove from the oven and allow to cool for 10 minutes before serving. (Delicious with or without a dollop of (failsafe) vanilla ice cream.)