• Preheat oven to 375º Grease a 13x9 baking pan with butter or cooking spray.
• In a large bowl, combine rhubarb, strawberries, and blueberries.
  2 cups rhubarb, 2 cups fresh strawberries, 1 cup fresh blueberries
• Add sugar, cornstarch and balsamic vinegar. Toss and stir until well coated.
  1 1/2 cups granulated sugar, 2 Tablespoons cornstarch, 1 Tablespoon balsamic vinegar
• Place sugared fruit mixture into prepared pan and set aside.

Make the Topping

• Mix together flour, sugar, salt and sliced almonds. Stir in egg until crumbly. Toss with your fingers to make sure it's completely combined.
  1 cup all-purpose flour, 1/2 cup granulated sugar, 1/2 teaspoon salt, 1/3 cup sliced almonds, 1 large egg
• Crumble over top of sugared fruit in pan. Drizzle with melted butter.
  3 Tablespoons unsalted butter
• Bake in preheated oven for 35-40 minutes or until topping is golden brown and mixture is bubbly.
• Cool until slightly warm. Serve warm topped with vanilla ice cream.