Mix the sugar and cinnamon together. Set aside. Line a tray with parchment paper.
Heat the water, sugar, salt and butter in a saucepan over medium heat. Bring to a boil then turn heat off and immediately add all the flour. Stir the flour vigorously with a wooden spoon until the dough forms a ball. Set aside for to cool down a little but pipe while the dough is still warm and pliable. Fit a large piping bag with a large closed star tip. Spoon the dough into the bag and carefully pipe the heart on the tray.
Heat the vegetable oil in a pot to 375F. Lower the hearts into the oil using a wooden spoon (to keep the shape well). Use chopstick to flip and fry until golden brown. Drain on kitchen towels and then roll the churros in the cinnamon sugar.
To Make the Chocolate Sauce: Heat the cream until just boiling then pour it over the chopped chocolate. Stir until the chocolate is melted. Drizzle is over the churros or dip the churros in the sauce. Serve warm.
