When making churros with chocolate dip to start with, heat the liquid ingredients to make sure the butter has melted and the sugar completely dissolved. Once this has happened, bring the mixture to a rolling boil before adding in the flour and salt. This step of boiling is really important as it will help the mixture thicken enough to pipe easily. If not, it will end up a loose mixture that will not pipe and just spread in a blob.
Add all the flour and salt to the liquid ingredients in one go and stir vigorously to combine. The mixture will eventually come together into a thick ball of dough.
Leave the dough to cool a little before adding the eggs, or you will end up with scrambled eggs in the batter! Whilst on this, keep in mind the dough will still be hot when adding the eggs, so be sure once more to mix vigorously when adding the eggs, doing so one at a time.
For ease, I like to use an electric hand whisk to beat in the eggs, but you could also use a handheld whisk or a wooden spoon. Please keep in mind that the dough will be very thick and stiff, so you need sturdy tools and a strong arm!
It may feel the eggs are not combining with the mixture, but be patient and keep mixing. It will come together in the end, I promise!
When transferring the mixture to your piping bag, make sure to push out any air bubbles and only fill half full. Filling more could result in the mixture pushing out the top whilst piping, leaving you with a bit of a mess! I partly fill my bag, pipe a few churros, then top up the mixture to continue piping.
Make sure to leave enough space in between piping the hearts for the churros to expand as they bake. This is not only important so they remain separate, but also as it will allow them to brown better if spaced apart.
Allow the churros to bake until a deep golden brown colour. If the oven is turned off too soon, they may be baked but will remain soft and not be crisp. You want them to be closer to a dark golden colour than a pale one.
To keep the crisp shell of the churros, I also like to lightly pierce them when removed from the oven before leaving to cool on a cooling rack. This allows any additional moisture in the churros to escape, leaving me with a beautiful crisp churro shell.