Preheat your oven to 400°F (200°C). Line a baking sheet with parchment paper.
In a large bowl, toss the halved baby potatoes with olive oil, salt, black pepper, and garlic powder until evenly coated.
Spread the potatoes in a single layer on the prepared baking sheet. Roast in the preheated oven for 25-30 minutes, or until golden brown and tender, stirring halfway through.
While the potatoes are roasting, prepare the creamy garlic sauce. In a small saucepan over medium heat, combine the heavy cream and grated Parmesan cheese. Stir continuously until the cheese is melted and the sauce is smooth.
Remove the sauce from heat and stir in the chopped parsley and lemon juice. Adjust seasoning with salt and pepper if needed.
Once the potatoes are done roasting, transfer them to a serving dish and drizzle the creamy garlic sauce over the top. Garnish with additional parsley if desired.