In a large mixing bowl, combine the bread flour, all-purpose flour, kosher salt, 3 Tbsp. sugar, instant yeast, and baking soda.

Gradually add water and mix until a dough forms.

Knead the dough until smooth and elastic.

Allow the dough to rise until it doubles in size.

Shape the dough into bagels and let them rest.

Boil water in a large pot and add the remaining sugar.

Boil each bagel for a short time before transferring them to baking sheets.

Add desired toppings to the bagels.

Bake in a preheated oven until golden brown.