Roast the sweet potato: Preheat the oven to 425 degrees F. Place the sweet potato on a baking sheet and roast until completely tender and easily pierced with a knife, about 1 hour and 10 minutes. Let cool, then remove and discard the skin.

Prepare the biscuits: Lightly flour a clean work surface. Separate the biscuits and carefully split each one horizontally into two even layers. Using your hands or a rolling pin, gently flatten each layer into a round.

Assemble the hand pies: Spoon about 2 tablespoons of sweet potato filling into the center of one biscuit round. Top with a second round and press the edges together with a fork to seal. Fold and roll the edges inward with your fingers to create a tight, rope-like crimp. Repeat with the remaining biscuits and filling to make 8 hand pies.

Fry the hand pies: Add about 1 inch of peanut oil to a 12-inch cast-iron skillet and heat to 375 degrees F. Working in batches of four, carefully add the hand pies to the hot oil. Fry until golden brown and cooked through, about 4 minutes total, flipping every minute to prevent overbrowning. Adjust the heat as needed to maintain the oil temperature. Transfer to a wire rack to drain and cool slightly.

Make the glaze: In a medium bowl, whisk together the confectioners' sugar, vanilla bean paste and cinnamon paste. Gradually add the milk, 1 tablespoon at a time, whisking until smooth and thick but pourable.

Glaze and serve: While the hand pies are still warm, dip one side of each into the cinnamon-vanilla glaze, allowing any excess to drip off. Return to the wire rack, glazed-side up, and let stand until the glaze is set. Serve warm or at room temperature.