• Mix the flour, sugar, salt and powdered milk in the bowl of an electric mixer, fitted with the hook.
• Make a well in the middle and add the crumbled yeast and warm milk. Knead until you get a smooth dough that comes off from the sides of the bowl.
• Add the butter gradually. Work the dough for about 10 minutes. You must obtain a smooth and homogeneous paste.
• Shape into a ball, cover with a cloth and let it sit in a warm (and draft-free) place for 1.5 to 2 hours, until doubled in size.
• At the end of the rising time, de-gas the dough. Form 12 rolls, place them on a baking sheet covered with parchment paper or a silicone mat. Be careful to leave some space between the dough pieces, as they will expand. Leave to rise for about 40 minutes (always in a warm, draft-free place).

Preheat oven to 200°C (400°F)

• Using a brush (or paper towel), baste with egg yolk mixed with a little milk, and sprinkle with large grains of sugar, if desired.
• Make small incisions on the top (with a baker's knife, a knife or even a scissor).
• Bake for 15 minutes, until golden brown. Let cool.