In a small, shallow bowl, stir together the sugar and cinnamon.

In a small saucepan over medium heat, whisk together the water, sugar, salt and vegetable oil. Bring the mixture to a boil then remove it from the heat. Stir in the flour, mixing until it forms a smooth ball.

Heat 3 to 4 inches of vegetable oil in a large, heavy-bottomed stockpot set over medium-high heat until it reaches 375ºF. Line a plate with paper towels.

Transfer the dough to a cloth pastry bag or heavy-duty plastic bag fitted with a large star tip (optional).

Pipe the dough over the pot of oil to a length of about 4 inches, then using scissors or a sharp knife, cut it so it releases into the oil. Pipe two to three churros into the oil at a time, frying them until they're golden brown and cooked through.

Transfer the churros to the paper towel-lined plate to drain for 2 minutes, then while they are still hot, roll them in the cinnamon-sugar mixture. Repeat the frying and coating process with the remaining dough.

Place the chopped chocolate in a small bowl.

Warm the heavy cream in a small saucepan. Pour the heavy cream over the chopped chocolate. Let it sit for 1 minute then stir to combine.