Prepare the topping: Combine all the topping ingredients in a bowl and mix with your hands until no longer dry, forming small "nuggets" of topping. Alternatively, use an electric mixer to combine everything. Using your hands, arrange the crisp topping on the filling and place the baking dish or skillet on a rimmed baking sheet. Bake for 40 to 50 minutes, or until the fruit is soft and bubbling and the topping is golden brown. If the topping is getting too golden before the fruit is soft, tent with aluminum foil. Serve warm with yogurt, if desired.