You can make this delightful dessert gluten-free by using gluten-free flour and oats. Try serving with vanilla ice cream or frozen yogurt.
Per serving:
Preheat oven to 350 F (180 C). Combine oats, walnuts, sugar, flour, cinnamon, and cardamom in medium bowl. Drizzle with oil and stir until evenly moist. Add more oil if necessary.
In separate bowl, combine fruit, maple syrup, raisins, flour, lemon juice, and ginger, and mix well. Transfer fruit mixture to lightly greased 9 x 9 in (23 x 23 cm) cake pan or cast iron skillet and spread out evenly. Spread oat topping over fruit mixture.
Bake until topping is golden, about 50 minutes. Let cool for 10 minutes before slicing.