Combine water, butter, brown sugar, and salt in a pot and bring to a rolling boil.

In a separate bowl, whisk together flour, 1 teaspoon cinnamon, and cocoa.

Remove the boiling water mixture from heat and add the flour mixture, stirring until combined.

Add eggs and vanilla to the dough and mix well.

Transfer the dough to a pastry bag fitted with a 1M Wilton tip (or cut a corner off the bag).

Heat about 1 inch of cooking oil in a fryer or large pan to medium-high heat.

Pipe 3-4 churros at a time into the hot oil.

Cook for about 1 minute per side, until golden brown.

Remove the churros from the oil and let them cool and drain on a wire rack or paper towels.

Mix the remaining sugar and cinnamon in a bowl.

Roll the cooled churros in the cinnamon-sugar mixture to coat.

Serve with chocolate sauce for dipping.