Make the Salad: Preheat oven to 425 degrees F.
In a roasting pan, combine the potatoes, 3 tablespoons of the olive oil, rosemary, salt, pepper, cumin and ginger. Stir to combine and bake until the potatoes are fork-tender and golden brown, about 25 to 30 minutes.
Meanwhile, heat the remaining 2 tablespoons olive oil in a skillet over medium-high heat. Add the pumpkin seeds and cook, stirring, until toasted. Transfer the seeds to a plate and season with salt and pepper. In a small bowl, combine the cranberries, scallions, and red pepper and set aside.
Make the Dressing: Prepare the dressing by combining all the ingredients (except for the olive oil) in a small saucepan and heat. Remove from heat and whisk in the olive oil.
Assemble salad by gently tossing the roasted potatoes with the red pepper mixture. Add enough of the dressing to coat and garnish with toasted pumpkin seeds. Serve with extra dressing on the side.