Over low/medium heat melt butter, add your water, sugar and a pinch of salt. Reduce your heat and mix in your flour so you create a batter.
Remove pan from the heat and let it sit to cool slightly for 10 minutes. Then add vanilla and room temp eggs into a bowl and use a hand mixer to combine everything into a sticky dough.
Transfer mixture into your piping bag with the correct churros shaped tip attached. Line a baking sheet with parchment paper and pipe as many as you can on to the sheet without them touching.
Place into the freezer flat for 1-2 hours until firmed. Preheat air fryer to 375 degrees F for 5 minutes. Spray inside of basket with non stick spray.
Transfer raw churros into basket without touching. Spray tops with olive oil spray and cook for 10 minutes until golden brown.
Pour chocolate into a new pastry bag with piping tip attached. Pick up cooked churro and gently insert long tip into pastry 3/4 of the way in and gently squeeze while pulling the long tip out slowly until filled to the end.
Pour cinnamon and sugar into a shallow bowl or on a plate, immediately roll into mixture to coat and enjoy!!