Preheat oven to 450F
Peel and coarsely grate sweet potatoes. Transfer to a colander and sprinkle with salt. Set aside.
Separate broccoli and cauliflower into bite size florets. Transfer to baking pan and drizzle with 2 tbsp olive oil.
Place baking sheet into oven and roast, stirring halfway through, until vegetables are tender, 18-20 minutes
Juice lemon into a small bowl. Add tahini, 2 tbsp water, maple syrup, 1/2 tsp chili powder, smoked paprika, salt, and pepper. Set aside.
Squeeze out excess moisture from sweet potatoes and place in a bowl. Add minced ginger, minced garlic, eggs, flour, soy sauce, 1 tsp chili powder, salt, pepper, and cumin. Using your hands, mix to combine the batter.
Preheat a large skillet over medium heat. Add remaining 2 tbsp olive oil. Working in batches, use a scant 1/4 cup measure to drop batter into skillet, placing scoops a couple inches apart. Flatten slightly with the back of a spoon. Cook, flipping once, until fritters are golden brown and cooked through, 6-8 minutes. Add oil as needed.
Shave dill leaves and roughly chop. Place in large bowl with half of tahini sauce. Add vegetables to bowl and toss to coat. Add pumpkin seeds and raisins, and toss to combine.
To serve, divide vegetables and fritters between plates. Top with remaining tahini.