Make a volcano in a bowl with the flour and set aside. Place the cold water in a bowl, with the sugar, the yeast and the egg and mix all the liquids. Then this mixture of liquids will be added to the flour and butter and we proceed to knead for about 7 minutes, immediately add the salt, vanilla, grated chocolate and chia seeds and knead for 3 minutes. Let this dough stand for an hour. Then we proceed to assemble our bread in the desired way, we varnish it with the egg white and the remaining sugar, we proceed to take it to the oven for 20 minutes at a temperature of 200 ° C.

Note: Always remember that yeast must be worked or prepared in a cold environment with all liquids.