Step 1: Combine cinnamon and sugar in a large deep container. I usually use an aluminum pan.
Step 2: Bring butter water and salt to a boil in a large saucepan. I used a dutch oven.
Step 3: Reduce heat to medium and add flour all at once to wet mixture. Stir frequently and evenly (with a wooden spoon or silicone spatula) to ensure mixture is incorporated. The mixture will pull away from the sides and form a dough and you will know it’s time to remove it from the heat.
Step 4: Transfer mixture to a Kitchenaid stand mixer bowl (or a large bowl if you will be using a hand mixer.
Step 5: Add eggs and vanilla to bowl and mix with paddle attachment until mixture forms a dough and the bowl feels cool and no longer hot.
Step 6: Transfer dough to a disposable piping bag fitted with a Wilton #1M Open Star Tip. Meanwhile, heat 2 inches of vegetable oil in a large frying pan on medium-high heat.
Step 7: Pipe a six inch length of dough into the hot oil to check that is ready. Cook for 2 minutes per side until a beautiful light golden brown. If your test churro cooks to quickly or not quickly enough adjust the heat accordingly. Continue to fry churros about 6 at a time, do not overcrowd the pan or the churros will not cook evenly!
Step 8: Transfer cooked churros to a plate lined with paper towel.
Step 9: Toss churros in cinnamon sugar mixture with tongs and transfer to a large platter or rimmed cookie sheet lined with parchment paper. Serve warm and enjoy!