I started working on ricotta cheesecakes last summer and gave up after several tries. I hated the grainy texture of every one I made. Recently, after several new unsuccessful attempts to achieve the ricotta cheesecake that I imagined in my mind, I had a conversation with the head baker at my local kosher bakery about the science of cheesecakes. He suggested gently blending in the ricotta last to avoid adding too much air to the mixture, and it made all the difference. I finally enjoyed the tasty and creamy ricotta cheesecake I knew was possible.
Preheat oven to 350 degrees Fahrenheit. Grease a 9 x 13-inch pan with some butter. Set aside.
In the bowl of a stand mixer place the cream cheese and sour cream and mix until combined. Add the eggs, one at a time and mix on low speed to incorporate each one. Add the sugar, lemon zest, vanilla and flour and mix in. Finally, add the ricotta and fold in gently. Pour into the prepared pan and bake for one hour and 20 minutes to one hour and 30 minutes, or until set.
Remove from oven and let cool slightly. You can eat it warm or after it has chilled in the fridge for three hours. Served scooped up with a spoon or cut into squares.
Store in the fridge for up to four days.