#1 Preheat oven to 375°F.  In a large mixing bowl, combine peaches, nectarines, blackberries, raspberries, sugar, 1 tbsp flour, lemon juice, and vanilla. Toss gently and pour into a greased 8-inch baking dish #2 In the same bowl, mix oats, ½ cup flour, brown sugar, cinnamon, and salt. Add cold cubed butter and work it in with your fingers until crumbly.  Sprinkle the oat topping evenly over the fruit #3 Bake for 30–35 minutes, until golden and bubbling.  Cool slightly before serving. Enjoy warm with a scoop of ice cream or whipped cream, enjoy!