Preheat oven to 325°F (165°C). Grease a 9-inch springform pan.
In a large bowl, blend ricotta and cream cheese until smooth using an electric mixer.
Add sugar, flour, orange zest, lemon zest, vanilla extract, and salt. Mix until fully combined.
Beat in the eggs one at a time, mixing well after each addition.
Stir in the melted butter until the batter is smooth and creamy.
Pour the batter into the prepared springform pan.
Bake in the preheated oven for 75 to 85 minutes, or until the center is set and the top is golden brown.
Turn off the oven, leave the cheesecake inside with the door slightly ajar for 1 hour.
Remove from oven and let cool completely. Refrigerate for at least 4 hours or overnight before serving.