1. Preheat your oven to 400°F. Lightly grease a large baking sheet or line it with parchment paper to prevent sticking.

2. In a large bowl, toss the quartered baby potatoes with olive oil, salt, black pepper, garlic powder, and the ranch dressing mix. Ensure the potatoes are evenly coated with the seasoning.

3. Spread the seasoned potatoes in a single layer on the prepared baking sheet. Roast them in the preheated oven for 20 minutes, flipping them halfway through the cooking time.

4. After 20 minutes, remove the pan from the oven and add the sliced smoked sausage to the potatoes. Toss the ingredients gently to combine, then return the pan to the oven for an additional 15-20 minutes, or until the potatoes are tender and golden brown.

5. Once the potatoes and sausage are perfectly cooked, sprinkle the shredded cheddar cheese over the top. Return the pan to the oven for 3-5 minutes, just until the cheese has melted and become bubbly.

6. Remove the pan from the oven and sprinkle the chopped fresh parsley over the top, if using. Serve hot, with a dollop of sour cream on the side for those who desire an extra creamy touch.