Place the butter, sugar and milk in a pot. Stir on the stove until the sugar dissolves. Set aside until it returns to a moderate temperature.
Mix 1 kg flour, yeast and baking powder together. Then, add the musk and the fenugreek.
Beat the eggs and vanilla until mixture becomes fluffy. Add it to the butter mixture. Then, add the flour and knead. If the dough is very soft add more flour until it becomes, soft and sticky.
Cover, with a nylon film and cloth. Leave to rest for 2 hours. Knead again and let rest to double in size.
Coat your finger with little of oil, then, take a piece of dough and make the shape you prefer. Place it on a tray.
Continue the same procedure until the dough has finished.
Beat the egg white, vanilla and 1 tablespoon milk.
Brush the top of brioche with egg whites.
Bake in the oven until golden.