Summer Berry Crisp

Ingredients

2 tablespoons unsalted butter, cut into cubes, plus 1 tablespoon for the pan
1 pound fresh or frozen IQF blackberries (no need to thaw any of the berries if using frozen)
1 pound fresh or frozen IQF blueberries
1 pound fresh or frozen IQF strawberries
3⁄4 cup granulated sugar
1⁄3 cup all-purpose flour
2 teaspoons vanilla extract
Brown Sugar Oatmeal Topping [3]
Whipped cream or vanilla ice cream, for serving (optional)

Preheat the oven to 375°F. Grease a 9 x 13-inch baking dish with the 1 tablespoon butter. Line a baking sheet with parchment paper or aluminum foil.
In a large bowl, combine the cubed butter, berries, granulated sugar, flour, and vanilla. Toss well to mix. Transfer the fruit to the prepared baking dish and cover with the oatmeal topping.
Place the baking dish on the baking sheet to catch any juices that may bubble over. Bake until the crisp is browned on top and the juices have thickened around the edges, about 50 minutes.
Serve warm or at room temperature with whipped cream or vanilla ice cream, if desired.