01 - Preheat oven to 350°F. Lightly grease a 9-inch square or round baking dish with butter or nonstick spray.
02 - In a large mixing bowl, combine the mixed berries, granulated sugar, cornstarch, lemon juice, and vanilla extract. Gently toss until the berries are evenly coated, then pour the mixture into the prepared baking dish and spread into a uniform layer.
03 - In a separate bowl, whisk together the rolled oats, all-purpose flour, shredded coconut, brown sugar, and salt. Pour in the melted butter and vanilla extract, stirring until the mixture becomes crumbly and all dry ingredients are well coated.
04 - Sprinkle the coconut topping evenly over the berry filling, covering the surface as uniformly as possible.
05 - Bake for 35 minutes, or until the topping is golden brown and the berry juices are bubbling around the edges.
06 - Allow the crisp to rest for 10 minutes before serving. Serve warm with a scoop of vanilla ice cream or a dollop of whipped cream if desired.