Add about an inch of oil to a heavy-bottomed pan and place it over medium heat. Allow the oil to heat to approximately 350°F. Line a small sheet pan or large plate with several layers of paper towels and set aside for draining the finished fritters.

In a large bowl, combine the all-purpose flour, cornmeal, sugar, baking powder, salt, pepper, garlic powder, and paprika. Whisk or stir thoroughly to ensure all the seasonings are evenly distributed throughout the flour mixture.

Add the cold milk and lemon juice to the bowl with the dry ingredients. Stir until just combined, being careful not to overmix. The batter should be slightly lumpy, which is perfectly fine and helps create a lighter texture.

Add the diced yellow onions and chopped green onions to the batter. Quickly stir everything together until the onions are well coated with the batter. Work swiftly to maintain the batter’s light texture.

Carefully spoon a heaping tablespoon of batter at a time into the hot oil. Make sure not to overcrowd the pan, leaving adequate space between each fritter so they fry evenly and don’t stick together. You’ll need to work in multiple batches.

Fry each fritter for 3 to 4 minutes per side, depending on their size. The fritters should develop a deep golden-brown color and crispy exterior. Flip carefully using a slotted spoon, then fry the other side for another 3 to 4 minutes.

Transfer the finished fritters to the paper towel-lined plate to drain excess oil. Continue frying the remaining batter in batches, allowing the oil to return to temperature between batches. Serve immediately while hot and crispy with your favorite dipping sauce.