Fill a deep frying vessel (such as a wok or deep skillet) with oil, leaving enough space for the oil to expand when heated. Heat the oil to 350°F (177°C) using a candy or meat thermometer to monitor the temperature.
In a large mixing bowl, combine the flour, baking powder, baking soda, salt, and ground cinnamon. Whisk until well combined.
In another mixing bowl, whisk together the eggs, milk, and vanilla extract until fully combined. Add the granulated sugar and whisk again until incorporated.
Pour the wet ingredients into the bowl with the dry ingredients. Mix until just combined, being careful not to overmix. The batter should be smooth and lump-free.
Transfer the batter into a squeeze bottle with a large enough spout to allow the batter to flow easily. This will make it easier to pour the batter into the hot oil.
Once the oil reaches 350°F (177°C), carefully squeeze the batter into the hot oil in a circular motion, starting from the center and working your way outwards to create a spiral shape. Fry until golden brown, about 1-2 minutes on each side.
Using tongs or a slotted spoon, carefully flip the funnel cake to cook the other side until golden brown. Once cooked, transfer the funnel cake to a plate lined with paper towels to drain excess oil.
Generously dust the warm funnel cake with powdered sugar using a fine mesh strainer.
Serve the funnel cake warm with your favorite toppings, such as strawberry syrup or any other desired toppings.
For a twist, you can also use the same batter to deep fry Oreos. Simply dip the Oreos in the batter, ensuring they are completely coated, and fry until golden brown. Serve warm with powdered sugar dusting.