Begin by heating enough oil to coat the bottom of whatever pan you are using. Use high heat.
Working quickly, combine the cinnamon and sugar in a small bowl. Set aside.
Peel, core and slice apples. Toss in cornstarch.
Once the oil is hot, test a small piece of apple to be sure it sizzles. If not, give it another minute or two.
Place a few of the cornstarch-coated apples into the hot oil and fry on each side for about 3 minutes. They should be just golden brown.
Line a cookie sheet with paper towels and transfer the cooked apples to drain for a few minutes.
Toss in the cinnamon sugar mixture.
Combine the whipped topping and vanilla and top with leftover cinnamon sugar to serve.