1. Preheat oven to 425 degrees. Using a vegetable peeler or paring knife, peel pumpkin or squash. Trim stem, then halve pumpkin or squash and scoop out seeds (save for roasting if desired). Cut flesh into 1-inch cubes.
2. Spread cubes out on a large rimmed baking sheet. In small saucepan, combine butter or canola oil, syrup, 1 teaspoon vinegar, kosher salt, 1/2 teaspoon black pepper and cayenne. Cook, stirring, over medium-high heat until butter melts; pour mixture over squash and toss to coat evenly. Roast, tossing occasionally, until pumpkin or squash is very tender and caramelized at edges, about 30 minutes.
3. In a large skillet, warm olive oil over medium heat. Add leeks, garlic, rosemary and a generous pinch of salt. Cook, stirring occasionally, until leeks are very soft and not at all browned, about 15 minutes. Add beans and broth and simmer for 10 minutes.
4. Stir in kale. Simmer until kale is cooked down and very tender, about 10 minutes. Stir in pumpkin or squash and chopped cranberries; season with remaining 1 1/2 teaspoons vinegar and 1/2 teaspoon black pepper. Garnish with additional cranberries and sea salt, and serve.