Preheat oven to 325°F (163°C). Grease a 9-inch springform pan.
Make the crust: In a bowl, mix graham cracker crumbs, sugar, and salt. Stir in melted butter until fully combined. Press the mixture firmly into the bottom of the springform pan. Set aside.
Make the filling: In a large bowl or stand mixer, beat the softened cream cheese and ricotta until very smooth. Scrape down sides as needed.
Add sugar and vanilla. Beat again until incorporated.
Add eggs and yolks one at a time, mixing well between additions.
Sprinkle in flour and gently mix just until absorbed.
Stir in lemon juice and zest until just blended. Do not overmix.
Pour filling over the prepared crust. Smooth the top with a spatula.
Wrap the bottom of the springform pan in multiple layers of foil.
Place the pan into a larger roasting pan. Slowly pour very hot water into the roasting pan until it reaches halfway up the sides of the cheesecake pan.
Carefully transfer to the oven. Bake for 1 hour 20 minutes. Turn off oven and let it sit inside for 45 minutes (don’t open the door).
Remove cheesecake from oven, run a knife around the edge, and cool for 15 minutes. Cover with plastic wrap and chill at least 6 hours or overnight.
Before serving, top with whipped cream if desired. Slice and enjoy!