For the crust and crumb:
1 1/2 cups all-purpose flour
1 cup firmly packed dark brown sugar
1 1/4 cups rolled oats
3/4 teaspoon salt
3/4 teaspoon baking powder
1/2 teaspoon baking soda
1/2 teaspoon cinnamon
3/4 cup (1 1/2 sticks) unsalted butter, cut into 1-inch pieces

For the raspberry filling:
1/4 cup firmly packed dark brown sugar
1 tablespoon grated lemon zest
1/2 teaspoon cinnamon
2 tablespoons all-purpose flour
1 pound raspberries, fresh or frozen
1/4 cup fresh lemon juice
2 tablespoons unsalted butter, melted and cooled