Prepare the Cinnamon Sugar Coating: In a shallow bowl, mix the granulated sugar and cinnamon together. Set aside.

Make the Churro Dough: In a medium saucepan, combine the 1 tablespoon sugar, butter, water, and salt. Bring to a boil over medium heat. Once boiling, remove from heat and immediately stir in the flour. Mix thoroughly until a cohesive dough forms that easily detaches from the edges of the pan. Allow the dough to cool for 5 minutes, then add the beaten eggs gradually, stirring until the mixture is smooth and fully combined.

Heat the Oil for Frying: In a deep pot, heat about 2 inches of vegetable oil to 350°F (180°C). Use a thermometer to maintain the oil temperature.

Pipe and Fry the Churros: Transfer the churro dough into a piping bag fitted with a large star tip. Pipe 4-5 inch strips of dough directly into the hot oil, cutting with scissors as you go. Sauté each side for 2 to 3 minutes, or until they develop a beautiful golden-brown color and a delightful crispy texture. Remove churros from the oil and place them on a paper towel-lined plate to drain.

Coat the Churros: Roll each churro in the cinnamon sugar mixture until fully coated.

Stuff with Nutella: Use a piping bag with a long, thin tip filled with melted Nutella. Carefully insert the tip into one end of each churro and pipe in the Nutella until the churro feels slightly full.

Serve and Enjoy: Serve the Nutella-stuffed churros warm and enjoy immediately.