Preheat your oven to 425 degrees. line 2 baking sheets with parchment and set aside.
Bring milk, sugar, butter, and salt to a full boil in a medium saucepan. Stir continually until the butter melts.
Add the flour all at once, stirring constantly.
When the dough balls up a bit and there is a thin film forming on the pan's bottom, you're ready to add the eggs. Place the contents in the bowl of a stand mixer.
Incorporate 5 of the 6 eggs, beating in one at a time. After you've added the 5th egg, lift the paddle. If the paste forms a loose peak there is no need for the additional egg. If not, beat in the last egg.
On the lined baking sheet, pipe 1 1/2 inch mounds of the paste about an inch apart. Use your fingers or a small spoon dipped in cold water to smooth out any peaks. Bake for 15 minutes, then reduce the heat to 375 degrees for about 10 minutes longer, or until they are golden brown and mostly firm.
Remove the puffs from the oven and cut a small slit, where you will eventually cut the cap off, to release steam. Turn off the oven and immediately place them back into the warm oven. Prop the door open with a wooden spoon and allow them to dry out inside for about 30 minutes.
Transfer to a wire rack to cool completely.