Place potatoes in a large pot, cover with cold water, and add salt.

Bring to a boil, then reduce heat and simmer until tender, about 20 minutes.

Drain potatoes well and return to the pot over low heat for 1 minute to evaporate excess moisture.

Pass the potatoes through a ricer or food mill into a large bowl.

Incorporate the butter, heavy cream, nutmeg, and pepper until smooth.

Stir in the egg yolks until fully combined.

Transfer the mixture to a pastry bag fitted with a large star tip.

Pipe the potatoes into 3-inch wide mounds onto a parchment-lined baking sheet.

Brush lightly with melted butter.

Bake at 400°F (200°C) for 15-20 minutes until the edges are golden brown.