Preheat the oven to 425 degrees Line a baking sheet with parchment paper.
Lightly brush the cut sides of the sweet potatoes with olive oil and arrange cut-side down on the baking sheet. Transfer to the oven and cook until quite soft, about 35 minutes. Remove the pan and set aside. When the potatoes are cool enough to touch, scoop out the flesh and measure out a total of approx. 2 cups. Transfer to a medium mixing bowl and mash with a fork.
Meanwhile, heat 1 tablespoon of olive oil in a medium nonstick skillet. Add the kale, chili powder and smoked paprika. Sauté until the kale is fully wilted, the liquid has evaporated, and the spices are fragrant, about 4 minutes. Transfer to a mixing bowl with sweet potatoes.
In a separate small mixing bowl, combine the flax seed meal with 2 tablespoons water. Mix until thoroughly incorporated and set aside for 5 minutes. Once gelatinous, transfer to a mixing bowl with the kale and sweet potatoes. Fold in the breadcrumbs and salt until the dry ingredients are well combined with the veggies.
Line a second sheet pan with parchment paper and lightly with oil. Using a melon baller or rounded tablespoon, portion the batter into 32 mounds, 16 on each tray. With your hands, shape the balls into oblong nuggets, and pat smooth. Arrange an inch or so apart on the parchment-paper lined baking sheets. Transfer to the oven and bake until the nuggets have dried out and formed a nice brown crust on the bottom, 30 minutes. Flip the bites and return to the oven for 10 more minutes, until firm.
Serve immediately alongside your preferred dipping sauce, or freeze for later.