Mango-Pineapple Buckle

Ingredients

• 1 stick (1/2 cup) unsalted butter, room temperature, plus more for baking dish
• 1 small or 1/2 medium pineapple (about 1 3/4 pounds), peeled, cored, and cut into 1/2-inch pieces
• 2 ripe mangoes, peeled and cut into 1/2-inch pieces
• 2 tablespoons dark-brown sugar
• 3/4 cup plus 2 tablespoons all-purpose flour
• 1 teaspoon ground cinnamon
• 1/2 teaspoon salt
• 1/4 teaspoon baking soda
• 1/2 cup granulated sugar
• 1 teaspoon pure vanilla extract
• 2 large eggs