Pre-heat your oven to 350°F.
In a large bowl, mix the flour with the sugar, baking powder and sea salt.
Melt the butter and add it to the dry ingredients.
Warm up the milk a little bit and gradually add it to the rest of the ingredients while working the dough. If the dough is too dry or too sticky, add some flour or some milk 1 tbsp at a time to get a soft, non-sticky dough.
Divide the dough in 8. Roll out each ball to make a flange then join both ends to make a bagel shape.
Place the bagels on a non-sticking pan, dusted with some flour, then coat with the egg wash, Finish by sprinkling sesame seeds (or any other kind of topping) on top.
Bake the bagels in a pre-heated oven at 350°F for 25min.