I only name a recipe 'Jim's ...' when I've finished tweaking it and arrived at a final version.
There are as many churro recipes as there are Spaniards, so it has been difficult to end up with one with which I'm happy. Some use oil or marge instead of butter, some don't include fat of any sort, recipe proportions vary a great deal, and some aren't even based on a choux mix. However, the following is in my opinion the ideal.
The quantities below make a good plateful. I can't tell you exactly how many because some thieving toerag kept coming a nicking one!
85g unsalted butter
Pinch of salt
150g plain flour
¼ tsp baking powder
3 medium eggs, beaten
1 tsp orange flower water (optional - I use Mercadona's Agua Azahar)
Finely grated zest from a lemon (or from ½an orange)
1/4 cup sugar
1 tsp. ground cinnamon
Weigh the water into a saucepan and add a pinch of salt. Slice in the butter. Put the pan over heat to melt the butter and bring to the boil.
Sieve the flour and baking powder together. As soon as the water boils, remove it from the heat and quickly stir in the sifted flour and baking powder. Beat the mix with a wooden spoon until smooth and it comes away from the sides of the pan in a smooth mass.
Cool for a couple of minutes. Then gradually add the beaten eggs, beating well until the mixture is smooth and glossy. Add the orange flower water (if using) and grated zest with the last dollop of egg and mix until combined.
Cover the bowl with a tea towel and leave the batter to one side to rest for up to 30 minutes.
Mix the sugar and cinnamon
Remove the basket from the deep fat fryer to give a bit more space in it. Heat fryer until it reaches 180-190C. Test your oil by placing a small amount of dough in it. The dough should bubble up right away - if not, that means the oil is not hot enough and a soggy churro is on the way. If you haven't got a deep fat fryer, put about an inch of oil in a saucepan - you don't need any more as the churros float on the surface.
Fit a large piping bag with a large star-shaped nozzle. Before decanting the mix, fold down the top of the piping bag, put the batter in it, then undo the fold. That way, if you get any batter on the top of the bag, it will be inside.
Pipe 2 or 3 finger-length strips of batter directly into the pan, cutting off each strip with a pair of scissors. Do not cook more than this in one go or the oil will cool down and your churros won't rise properly, and will be soggy inside, rather than crisp, golden and light.
Turn the churros every half minute or so, so they cook evenly, until golden and crisp.
Remove them from the pan with a slotted spoon, drain quickly on kitchen paper, and sprinkle liberally with the sugared cinnamon. I put the churros on a plate before sugaring them, so the excess sugar can be re-used.