1. In a mixing bowl, whisk together the all-purpose flour, cornstarch, baking powder, and salt.
2. In a separate bowl, beat the egg, then add milk and vanilla extract. Mix well.
3. Gradually add the wet ingredients to the dry ingredients, stirring continuously to form a smooth batter. Ensure there are no lumps.
4. Heat oil in a deep fryer or a large, deep pan to 350°F (175°C).
5. Using a spoon or an ice cream scoop, carefully drop portions of the batter into the hot oil. Fry in batches to avoid overcrowding.
6. Fry the cakes for 3-4 minutes or until they turn golden brown and crispy. Use a slotted spoon to remove them from the oil and place them on a paper towel-lined plate to drain excess oil.
7. Allow the crispy fried cakes to cool slightly before serving.
8. Optional: Dust the fried cakes with powdered sugar for added sweetness.
9. Serve warm and enjoy your delicious crispy fried cakes!

These crispy fried cakes are versatile and can be enjoyed on their own or paired with your favorite dipping sauce. Experiment with different flavors or add-ins to customize the recipe to your liking!