Start by heating the olive oil in a large skillet over medium-high heat. Add the diced onion and sauté for about 5 minutes. You want the onion to become soft and translucent, stirring frequently to prevent burning. In the last minute of sautéing, toss in the minced garlic and cook until fragrant, about one minute more. This step builds a rich base of flavor.
Next, it’s time to transfer the sautéed onion and garlic mixture to your slow cooker. If you like, spray the ceramic base of the slow cooker with cooking spray to prevent sticking.
Now, let’s add the remaining ingredients: the pumpkin purée, carrots, sweet potatoes, and vegetable broth. Ensure all ingredients are well combined. Season with salt, black pepper, cumin, cinnamon, nutmeg, and cayenne pepper. Stir everything together, cover, and set your slow cooker to HIGH for about 4 hours or LOW for 6 hours. During cooking, give it a stir a couple of times to ensure even cooking.
The soup is done when the vegetables are very soft and easily pierced with a fork. This is key for achieving that velvety texture!
While the soup is cooking, prepare the optional croutons. In a separate large skillet, melt the butter over high heat. Once melted, add the Italian seasoning, salt, and pepper, stirring to combine. Toss in the diced bread cubes and coat them in the seasoned butter. Reduce the heat to medium and cook until the bread is golden brown and crispy, about 7 to 10 minutes. You want to toss and flip them frequently for even cooking.
If you prefer, you can also bake the croutons in a 375°F oven for about 15 to 20 minutes, flipping them halfway through. Just keep an eye on them to avoid burning.
When the cooking time is up, use a handheld immersion blender to blend the soup until it's smooth and creamy. This is where the magic happens!
Before serving, it’s essential to taste the soup. Adjust the seasoning as needed; if it tastes flat, it might need more salt or a dash more of cayenne pepper or cumin to enhance the flavor.
If desired, you can add a splash of coconut milk or other dairy for added creaminess. Top with fresh herbs before serving.
