Prepare all ingredients:
Bake the potatoes in robe des champs.
When finished, peel them...
...and smash them to obtain a light purée.
Place the flour in fountain.
Add the chopped ginger and the potato purée.
Add the eggs, butter cut into pieces...
...and knead the dough starting from the middle.
Mix the yeast in 4 tablespoons of warm water and leave to probe for 30 minutes.
Add the yeast to the dough...
...and knead well to obtain an elastic mass.
Place the dough in a mold,...
...cover with a cloth and leave to rise in a warm place for 1 hour.
When it reaches the edge of the mold, bake in hot oven for 40 minutes.
When finished, remove from the mold onto a rack and sprinkle with icing sugar.