Preheat oven to 425°F (220°C).
Place each potato between two wooden spoons or chopsticks and slice thin slits across the potato without cutting all the way through.
Mix melted butter, olive oil, and garlic in a small bowl.
Brush each potato with the butter mixture, making sure to get between the slices.
Season with salt and pepper.
Bake for 45-55 minutes, basting occasionally with more butter mixture until crispy and golden.
Sprinkle with fresh parsley and Parmesan cheese before serving, if desired.