Toss pears with caster sugar and water in a shallow 2 litre baking dish.
In a large bowl, combine flour, oats, sugar, cinnamon and salt. Mix to blend thoroughly. Rub in the butter until mixture resembles coarse crumbs. Mix in almonds. Crumble over pears to cover completely.
Bake for 40 to 45 minutes until top is lightly browned. Serve warm or at room temperature.