Heat the water, butter, 2 tablespoons of sugar, and salt in a medium saucepan over medium heat, until the butter melts and the mixture begins to boil. Add the flour and stir vigorously over low heat for 1 to 2 minutes, until the mixture is very dry. Transfer the mixture to the bowl of an electric mixer. With the mixer on medium-low speed, add the eggs one at a time, until the batter is smooth and glossy. Cover with plastic wrap and chill in the refrigerator for at least 1 hour, or overnight.
Preheat the oven to 425°F. Pour the condensed milk into a small, shallow baking dish and cover tightly with aluminum foil. Place the baking dish in a larger roasting pan. Fill the roasting pan with enough water to come halfway up the sides of the baking dish. Roast for 1 hour and 15 minutes, stirring once while cooking, until the milk turns a light golden color.
Pour enough oil into a large saucepan to come about two inches up the side of the pan. Place the oil over medium-high heat, until a deep-fry thermometer registers 350°F. Working in batches, use a small ice cream scoop to drop the batter into the hot oil. Fry the fritters for 2 to 3 minutes, until golden brown all over. Drain on paper towels.
Stir together the cinnamon and remaining ½ cup of sugar in a small bowl. While the fritters are still warm, roll in the cinnamon sugar and serve with the dulce de leche.