Preheat oven to 425 degrees. Prepare 2 baking sheets by lining with parchment paper. Set aside.
In a small saucepan, combine water, brown sugar, salt and butter and bring to a boil until butter is melted.
Remove from heat and add in the flour, stirring vigorously with a wooden or silicone spoon until it is fully incorporated. You should end up with a thick paste-like dough that pulls away from the sides.
Place the dough into the bowl of a stand mixer fitted with a paddle attachment and allow to cool for a minute or two. Mix in the vanilla extract. Crack in eggs one at a time, until they are fully incorporated and the batter is smooth {about 2 minutes}.
Scoop mixture into a piping bag fitted with a large open star tip. Pipe a swirl or pinwheel shape (about 2 ½ inches) Remember, they'll be sandwiches so try to make them roughly the same size so they have a matching pair.
Bake for about 12-14 minutes or until puffed and brown. The insides should be moist but not completely doughy. Meanwhile, in a small bowl, mix together the sugar and cinnamon and set aside.
When the churros are fully baked, immediately toss them into the cinnamon sugar to coat. Remove them and place onto cooled baking pan until ready to create sandwiches.
When the churros are cooled, take a scoop of dulce de leche ice cream and place it on one churro base. Top with another churro to create a sandwich and press lightly to adhere. Serve immediately or keep frozen until ready to serve.