Warm up milk (do not boil it) and add eggs and sugar.
Mix it together over a low heat until the mixture is warm, but not hot.
Add yeast and mix it further. Let it stand for 10 minutes so that the yeast activates.(wet mixture)
In a large bowl, add flour, salt, lemon juice, lemon zest, and vanilla.
Melt butter and let it cool for few minutes.
Combine the "wet mixture" with the flour, salt, lemon juice, lemon zest, and vanilla in a large bowl and mix it well together until the batter is smooth.
Add the melted butter and continue mixing.
Once thoroughly mixed, let it stand for 25-30 minutes covered with a dish towel for the batter to expand.
Heat up the waffle maker and with a ladle pour enough batter to spread evenly throughout the iron space.
Each waffle takes about 4 minutes to bake.