Place the cashews in a small bowl and cover with water. Set aside.
Place the onions, garlic, vegetable stock, crushed tomatoes, sun-dried tomatoes, tomato paste, Italian seasoning, salt, and honey (if using) into the base of a slow cooker, stirring to combine.
Cook on high for 4 hours or low for 6 hours.
When the soup is finished cooking, drain, and rinse the cashews. Place into the slow cooker, stirring to combine.
Using an immersion blender, blend the tomato mixture until well combined and very smooth, about 2 minutes. If you don’t have an immersion blender, carefully ladle the cooked tomato mixture into a blender, working in batches. Make sure the lid is on tightly, cover with a towel, and blend until well combined and very smooth.
Serve hot, topping with scallions and basil if you like.
This creamy tomato soup is a great way to get kids eating their veggies. Here are some options for resistant eaters:
Let them help dump the ingredients in the slow cooker base and stir everything together (before it's on and heated up).
Skip the basil and green onion topping.
Soup can be hard for little hands to handle. Offer the warm soup in a mug for sipping instead of spooning.