Preparation

• Position a rack in the center of the oven and heat the oven to 375°F.
• Combine the brown sugar, flour, oats, butter, nutmeg, and 1/8 tsp. salt in a medium bowl. Using your fingers, rub in the butter until it’s about the size of small peas and the mixture resembles coarse, crumbly breadcrumbs; it should hold together when squeezed. Refrigerate, uncovered, while you make the filling.
• Put the pineapple in a large bowl. In a small bowl, combine the lime juice, ginger, and a pinch of salt and whisk to blend. Stir the lime mixture into the pineapple. Sprinkle the cornstarch over the pineapple and stir again.
• Transfer the pineapple to a 9-inch square baking dish and sprinkle the crumb mixture evenly over the top. Cover with foil and bake for 20 minutes. Remove the foil and continue to bake until the fruit is bubbling around the edges and the top is golden-brown and crisp, about 15 minutes more. Let cool for at least 15 minutes before serving.