For the dough: In a standing mixing bowl with a dough hook, add flour, sugar, salt & (1), milk, eggs. Mix for about 10 minutes until the dough becomes fluffy. Meanwhile put orange zest, vanilla, butter and knead well until the dough is smooth & elastic. To enhance orange flavor, add a tsp of orange blossom water. Place the dough in a bowl, cover and leave in a moderately warm place to double in size.