Bring water, butter, sugar, salt, and vanilla extract to a boil.
Stir in flour all at once.
Cook until paste comes together and pulls away from the pot.
Place dough in a mixing bowl; using the paddle attachment, combine eggs slowly, one at a time.
Use a pastry tip (#867 star) to pipe four churros onto parchment paper.
Drop into hot oil and cook until golden brown.
Once finished, roll in cinnamon and sugar.
Preheat oven to 425 F.
Pour the sweetened condensed milk out of the can and into a small baking dish, cover tightly with foil.
Place the covered baking dish into a larger baking dish or pan, and pour hot water into the larger pan until it is halfway up the sides of the smaller dish.
Bake in the oven for 2 hours, making sure the water stays full around the dish – refill as needed.
Let cool & whisk the dulce de leche to achieve smooth texture.
