In the crockpot, add the diced potatoes, broccoli, onion, and minced garlic.
Pour in the vegetable broth and stir to combine.
Season with salt, black pepper, and cayenne pepper (if using).
Drizzle the olive oil over the mixture for added flavor.
Cover the crockpot and cook on low for about 6 hours or until the potatoes and broccoli are tender.
Once cooking is complete, blend the soup using an immersion blender until it reaches your desired smoothness (or transfer to a blender in batches).
Stir in the heavy cream and shredded cheddar cheese until well combined and melted.
Taste and adjust seasoning if needed before serving.
Garnish with additional cheddar cheese, fresh herbs, or croutons before serving for extra flavor and presentation.