Scrub each potato under running water with a brush or rough sponge. Dry thoroughly — dry skin crisps instead of steaming. Poke all over with a fork or knife about 8 times per potato to let steam escape and heat the center evenly. Optionally rub skins with olive oil, salt, and pepper for extra flavor and crispiness. Line a baking sheet with foil or parchment, place potatoes on the sheet with space between them.

Precalienta el horno a 218°C y déjalo alcanzar completamente la temperatura. Coloca las batatas en una bandeja de hornear en la rejilla central. Hornea 45–70 minutos: las patatas medianas (5–6 oz) toman 45–50 minutos, las más grandes 60–70 minutos. A los 30 minutos, gira la bandeja 180°. Comienza a verificar la cocción a los 45 minutos. Algunos goteos caramelizados en la bandeja son normales a esta temperatura.

Fork test: insert a fork or thin knife into the thickest part — no resistance means it's done. Or squeeze gently through an oven mitt; it should feel soft and yield easily. If still firm at the center, return to the oven for 5–10 more minutes and test again. Remove from oven, rest 5 minutes. Split the top lengthwise, press the ends to open and fluff. Season with salt and pepper, then add toppings of your choice. Don't pull early — trust the fork test over how the skin looks.