In a large bowl, combine ricotta and eggs, and mix until smooth. Add flour, baking powder, salt, cinnamon, sugar, and vanilla. Mix again to make a smooth batter.
Fill a wide, deep skillet with about 2.5 centimeters of oil. Heat over medium-high heat until a bit of batter sizzles when dropped in. Using a spoon or ice cream scoop, drop rounded teaspoons of batter into the pan, five or six at a time. After about one minute, when the batter puffs up and the undersides turn golden brown, flip the balls and allow to brown again for about one more minute. Transfer the balls to paper towels, just to remove the excess oil, and continue frying until all batter is used.
Pile the ricotta balls in a pyramid shape on a serving plate. Using a sieve, sprinkle icing sugar evenly and generously over the ricotta balls. Serve immediately.