In a mixing bowl, whisk together the flour, baking powder, salt, and sugar.
In a separate bowl, beat the egg, then add milk and vanilla extract. Mix well.
Gradually add the wet ingredients to the dry ingredients, whisking until smooth and lump-free.
Heat vegetable oil in a deep fryer or large skillet to 375°F (190°C).
Pour the batter into a funnel or squeeze bottle.
Holding the funnel or bottle over the hot oil, drizzle the batter in a circular motion, starting from the center and working outward to create a lacy pattern.
Fry the funnel cake for 2-3 minutes on each side, or until golden brown and crispy.
Using tongs, carefully remove the funnel cake from the oil and drain on paper towels.
Dust generously with powdered sugar before serving.