Preheat the oven to 400 degrees F and line a large rimmed baking sheet with parchment paper or spray with oil.
Peel the carrots, then cut them into 1-inch thick diagonal pieces. Place on the baking sheet and drizzle with 2 tablespoons of olive oil. Toss to coat them in the oil, then sprinkle with a little salt and pepper.
Roast in the oven for 20-35 minutes, until fork-tender and golden on the edges. Be careful not to burn them. Larger carrots will take more time and small varieties will take less time in the oven. Remove from the oven and set aside.
Meanwhile, warm a tablespoon of olive oil in a large soup pot over medium heat. Add the onion and sauté for about 5 minutes, until translucent. Now add the garlic and ginger and sauté for 1 more minute, until fragrant.
Stir in the cinnamon, roasted carrots and then pour the vegetable broth in the pot. Bring the mixture to a boil, then lower the heat and simmer for about 10 minutes.
Remove the soup from heat and transfer (in batches if needed) to a high-powered blender. Carefully blend until silky-smooth, and return to the pot. Alternatively, use an immersion blender to blend in the pot.
Stir in the lemon juice. Taste; add more salt/pepper or more lemon juice, as desired.
Serve in bowls with a swirl of plain vegan yogurt, coconut cream, some cilantro or nuts/seeds. Enjoy!