SWEET POTATO FRIES: Meanwhile, cut the sweet potatoes into long fry-shaped pieces trying to keep the same size. Toss them with olive oil, ground cumin, smoked paprika, salt and freshly ground black pepper. Arrange them on a parchment-lined baking tray, trying not to overcrowd it. Bake for 15 minutes, then flip over and bake until ready, for about 12 minutes. The baking time highly depends on the size of your fries. Bake the rested pretzel buns for 15 minutes.