Vegetable oil, for frying
4 Granny Smith apples, peeled
1/2 cup cornstarch
1/2 cup plus 2 tablespoons granulated sugar
1 teaspoon ground cinnamon
2/3 cup heavy cream
1 teaspoon pure vanilla extract
Heat 1 1/2 inches of vegetable oil in a large wide pot over medium heat until a deep-fry thermometer registers 300 degrees F. Cut the apples into 1/2-inch-wide sticks to look like fries.
Working in two batches, toss the apples in the cornstarch until well coated, shaking off the excess. Fry in the hot oil until softened but still pale, about 2 minutes. Remove with a slotted spoon and transfer to a rack set over a rimmed baking sheet in a single layer; let cool. Let the oil return to 300 degrees F between batches.
Mix 1/2 cup sugar and the cinnamon in a shallow bowl; set aside. Beat the heavy cream, vanilla and remaining 2 tablespoons sugar in a medium bowl with a mixer until medium peaks form.
Increase the oil temperature to 375 degrees F. Working in about three batches, re-fry the apples until crisp and lightly browned, about 1 1/2 minutes. Remove to paper towels to drain briefly, then toss in the cinnamon sugar until well coated. Serve warm with the whipped cream for dipping.