Preheat your oven to 350 degrees.
Butter a 9 inch springform pan.
In a large mixing bowl beat together the egg yolks, sugar, vanilla and lemon zest with an electric mixer on high speed until fluffy, about 5 minutes.
Beat in the ricotta until well combined. Lower the speed to low and beat in 1/4 cup of the flour until fully absorbed.
In a separate mixing bowl using clean beaters beat the egg whites until soft peaks form and fold them into the batter.
Toss the cherries with the remaining 2 tablespoons of flour. This will ensure they do not sink to the bottom.
Fold the cherries into the batter and bake in the prepared pan for 50-60 minutes or until the center feels firm.
Cool the cake in the spring for 15-20 minutes before opening.