Combine the chocolate chips, cream, and corn syrup in a heavy bottom small saucepan and heat over low heat, stirring occasionally, until the chocolate is fully melted. Take off the heat and stir in the vanilla. Let cool while making the churros.
Churros
Combine 1½ cups sugar and the cinnamon in a large mixing bowl and set aside. Break the eggs into a liquid measuring cup or spouted pitcher and set aside.
Place the water, butter, ¼ cup sugar, and salt in a heavy saucepan over medium-high heat. Bring to a simmer. Add the flour all at once and stir with a wooden spoon until it forms a thick dough. Continue to cook while stirring for about 1 minute.
Dump the dough into the bowl of an electric mixer, preferably fitted with a paddle attachment. Mix on low speed for a minute to cool the dough slightly. Add the eggs, one at a time, mixing well after each addition. After all the eggs have been added, continue to mix, increasing the speed to medium-high, until the dough is smooth, thick and shiny, about 2 or 3 minutes.
Pour the oil into a pot or Dutch oven and heat to 350 degrees over medium heat.
Put the dough into a pastry bag with a large round or star tip and pipe out 6-inch lengths of dough directly into the hot oil. Fry for 2-3 minutes per side or until golden brown. Remove with a slotted spoon, let the excess oil drip off, then place the churros into the cinnamon sugar mixture. Toss gently to coat. Continue until all the dough is cooked. Serve with the chocolate dipping sauce.