In a medium-sized mixing bowl, whisk together the flour, sugar, cornstarch, and a pinch of salt until combined. Add the egg, vanilla extract, and water. Whisk until smooth (it should have the consistency of pancake batter).

Prepare the cinnamon sugar: In a medium-sized mixing bowl, whisk together the sugar, cinnamon, and salt until combined. Set aside until ready to use.

Pour oil halfway up the sides of a medium pan and set over medium heat. Once the oil is hot (you can tell it’s hot by dropping a little of the tempura batter into the oil – it should sizzle), turn the heat to low and toss the apple slices into the tempura batter, making sure they are completely coated.

Using a fork, take each apple slice, letting any excess batter drain off, and carefully place into the hot oil. Do not overcrowd the pan – you may need to work in batches. Cook until golden brown on each side, one to three minutes per side.

Remove the apple slices from the oil with a slotted spoon and transfer to a paper-towel-lined plate. Immediately toss into the cinnamon sugar mixture, coating completely. Serve immediately with the chocolate sauce drizzled on top or on the side.

Place the chocolate chips in a medium-sized mixing bowl.

In a small saucepot over medium-high heat, combine the cream and butter. Bring to a simmer, making sure the butter is completely melted. Pour over the chocolate and whisk until smooth with a pinch of salt. If you need to reheat, microwave at 15-second intervals, stirring in between, until warm.