In a large pot or Dutch oven, melt the butter over medium heat.
Add the diced onion and carrots to the pot. Sauté for about 5 minutes, until the onions become translucent.
Stir in the diced potatoes and corn, cooking for an additional 2 minutes.
Pour in the vegetable broth, and add the dried thyme, garlic powder, salt, and pepper. Bring the mixture to a boil, then reduce the heat to low and cover.
Simmer for about 20 minutes, or until the potatoes are tender.
Once the potatoes are cooked, use a potato masher or immersion blender to mash about half of the mixture to thicken the chowder, leaving some chunks for texture.
Stir in the heavy cream and heat through on low for another 5 minutes.
Taste and adjust seasoning with more salt and pepper if needed.
Serve hot, garnished with fresh parsley.