Preheat oven to 400°F (200°C). Line a baking sheet with parchment paper.
Toss halved baby potatoes in olive oil, salt, and pepper. Spread evenly on the baking sheet.
Bake for 25–30 minutes, flipping halfway, until golden and tender.
While potatoes roast, melt butter in a skillet over medium heat. Add garlic and sauté 1–2 minutes until fragrant.
Pour in heavy cream, simmer for 3–4 minutes until slightly thickened.
Stir in Parmesan until melted and smooth. Remove from heat.
Transfer roasted potatoes to a serving dish. Pour creamy garlic sauce over and toss lightly.
Sprinkle with parsley and serve hot.