01 - Bring a large pot of salted water to a boil. Add the potatoes and cook for 15–18 minutes, or until fork-tender.
02 - Drain the potatoes well. Return to the pot and mash until smooth.
03 - Stir in the butter and milk until fully incorporated. Season with garlic powder, onion powder, smoked paprika, salt, and pepper. Let the mash cool for 10 minutes.
04 - Add the egg to the cooled mashed potatoes and mix thoroughly.
05 - Transfer the mixture to a piping bag fitted with a large star tip, or shape by hand into fry-like sticks.
06 - For Baking: Preheat oven to 425°F. Line a baking sheet with parchment paper. Pipe or arrange the mashed potato sticks onto the sheet. Lightly brush with oil. Bake for 20–25 minutes, turning halfway, until golden and crisp. For Frying: Heat vegetable oil in a deep pot to 350°F. Carefully lower the shaped potato fries in batches. Fry for 2–3 minutes or until golden and crispy. Drain on paper towels.
07 - Serve hot, garnished with parsley or Parmesan if desired.