Now, grab a large mixing bowl and add your flour, salt, eggs, and softened butter. You can use a stand mixer with a dough hook if you have one, or just mix it by hand with a spoon. Slowly pour in the yeast mixture you created earlier. Once everything is combined, you should have a soft dough. If the dough is a bit too sticky, you can add a little more flour, but don’t go overboard—brioche dough is supposed to be slightly sticky.