Make ahead: prepare the crema. Combine the sour cream, heavy cream and 1 teaspoon salt in a bowl and cover with plastic wrap. Allow to sit out at room temperature for up to 3 hours, then refrigerate.

Preheat oven to 400 degrees. Line a large baking sheet with aluminum foil and set aside.

In a large bowl, toss together the carrots, apple and red onion. Coat with the olive oil, salt and pepper. Pour mixture onto baking sheet and arrange in a single layer.

Roast the vegetables for 25-30 minutes, removing the sheet from the oven about halfway through and stirring the vegetables a bit. Remove the roasted, tender vegetables from the oven and let cool slightly.

Place roasted veggies in the bowl of a food processor and add the cumin and 2 cups of the chicken broth. Close the lid and pulse to puree the veggies and broth, then continue adding broth in a steady stream with the food processor running until you get a good consistency for the soup.

Pour the soup into a saucepan and heat on medium-low heat until steaming. Spoon into bowls and garnish with crema and pepitas. Serve immediately.