How to Make It
Pour oil to a depth of 3 inches in a large saucepan; heat over high to 360°F. Meanwhile, stir together egg, pancake mix, bananas, buttermilk, vanilla, and cinnamon in a bowl using a fork until combined.
Working in 3 batches, gently drop about 4 spoonfuls of batter (1 heaping tablespoonful each) into hot oil. Cook until light golden brown and puffed, about 3 minutes per batch, flipping fritters halfway through cook time and adjusting heat as needed to maintain oil temperature of 360°F. Transfer fritters to a plate lined with paper towels using a slotted spoon. Let cool 2 minutes.
Dust fritters liberally with powdered sugar. Serve immediately.