In a bowl, whisk the eggs, egg white, salt, sugar, lemon zest and vanilla until fluffy.
Add the oil gradually while continuously whisking.
Add 3 cups sifted flour and baking powder.
Mix everything well, then add the rest of the flour until obtain a nice soft dough.
Form 2 logs of about 2.5 to 3 inches large.
Place the logs of dough on a baking sheet lined with parchment paper. Make sure to leave space between the logs.
Slightly flatten the surface of the logs.
Mix the egg wash ingredients and brush the logs on top.
Use a fork to make designs on top of each log.
Bake in a 350°F preheated oven for about 25 minutes or until golden.
Slice the logs slightly on an angle into pieces.
Put the pieces back in the oven if you want the sides to brown a little bit. Let brown for about 5 minutes on each side (optional).
Store in an airtight container.
Serve with coffee or tea.