A delcious and stunning dessert highlighting one of summer's best fruit with minimal effort required.
Preheat oven to 350F/175C.
Lightly butter a 2 quart baking/ casserole dish.
Combine plums, sugars, cornstarch, salt, cinnamon, and lemon juice in a large bowl and toss to combine. Set aside.
In a medium bowl, combine the all the dry ingredients for the topping and mix thoroughly. Add in the cubed, slighlty softened butter and either using a pastry blender, a fork, or your fingers, work it into the dry ingredients until everything is crumbly and the butter is in pea-sized pieces. Place the bowl into the freezer for 10 minutes.
When the topping is cold, pour the filling into the prepared dish, spread the topping evenly over the fruit and place in the middle rack of the oven. Bake for 35-40 minutes until the topping is golden brown and the plums are bubbling at the sides. (Mine took 38 minutes.)
Serve warm, room temperature, or cold with a scoop of vanilla ice cream on top. Store leftovers in the refrigerator.