Preheat the oven to 400°F (200°C). Scrub the russets, pat dry, and pierce each potato several times with a fork.

Rub with a little butter and place directly on the oven rack or on a baking sheet.

Bake for 45–60 minutes, until a skewer inserts easily.

Melt 1–2 tablespoons butter in a skillet over medium heat. Add the shrimp and crawfish and sauté just until shrimp turn pink and opaque, about 2–3 minutes. Remove from heat.

Return skillet to low heat. Add the softened cream cheese, half the shredded Cajun blend, green onions, Cajun seasoning, and a pinch of salt and pepper. Stir until cream cheese melts and everything becomes a smooth filling. Taste and adjust seasoning.

When potatoes are cool enough to handle, cut each lengthwise and carefully scoop out most of the flesh, leaving a 1/4-inch shell.

Fold the scooped potato flesh into the seafood mixture until combined.

Spoon the seafood-potato mixture back into each shell, mound slightly, and sprinkle remaining cheese on top if desired.

Return stuffed potatoes to the oven for 15–20 minutes, or until tops are bubbly and golden. For a crispier top, broil for 1–2 minutes at the end, watching closely.

Serve warm, garnished with chopped green onions and an extra pat of butter if desired.