Preheat your oven to 400ºF (200ºC). It’s essential to get your oven ready, ensuring an even bake for your casserole. Lightly spray a 9×13-inch dish with cooking spray to prevent sticking.
In a large bowl, combine ½ cup packed brown sugar, 2 Tbsp orange juice, 2 tsp vanilla, ½ tsp salt, 1 tsp pumpkin pie spice, and 2 Tbsp melted butter. Stir until well mixed; the mixture should have a smooth texture. This base is crucial for the flavor foundation of your casserole.
Add in the 3 pounds sweet potatoes (peeled and cut into 1-inch cubes) and 1 cup dried cranberries. Toss everything together to ensure the sweet potatoes are thoroughly coated with the sweet mixture. You'll want to see the cranberries interspersed throughout the mixture.
Pour the mixture into the prepared dish, spreading it out evenly. This ensures every bite will be packed with flavor.
Cover the dish with aluminum foil and bake it in the preheated oven for 30 minutes. This initial baking helps the sweet potatoes soften and absorb the flavors.
After 30 minutes, remove the dish from the oven. The sweet potatoes should be tender at this point. Set it aside to cool slightly.
While the casserole is cooling, prepare the topping. In a small bowl, combine ½ cup all-purpose flour, ¼ cup packed brown sugar, and 1½ tsp pumpkin pie spice. Mix well to combine.
Cut in ¼ cup cold butter until the mixture resembles coarse crumbs. Use your fingers or a pastry cutter to achieve the right texture; you want it to be crumbly.
Stir in 1 cup chopped pecans into the flour mixture. This addition will give your topping that much-needed crunch.
Sprinkle the topping evenly over the sweet potato mixture in the baking dish. Spread it out to cover the entire surface.
Bake uncovered for an additional 25 to 30 minutes, or until the casserole is bubbly and the sweet potatoes are tender. The topping should be lightly golden and crispy when done.
