Combine the yogurt and the ricotta the night before. Place the Greek yogurt and ricotta mixture in a cheesecloth-lined sieve set over a bowl. Cover and refrigerate overnight to drain.
Preheat the oven to 350°F. Stir the graham cracker crumbs with the melted butter until evenly moistened. Press firmly into the bottom of a 9-inch springform pan. Set aside.
Make the filling. Let the yogurt and ricotta mixture sit at room temperature for 20-30 minutes before making the filling. Add the strained yogurt ricotta mixture to a large bowl along with the honey, vanilla, and lemon zest, and stir well to combine. Add the eggs one at a time, beating just until each one is incorporated. Do not over-mix.
Bake. Pour the filling over the crust and gently smooth the top. Bake at 325°F for 55 to 65 minutes, until the edges are set and the centre still has a gentle wobble.
Cool gradually. Turn the oven off, crack the door, and leave the cheesecake inside for 20 minutes. Then move to the counter and let cool to room temperature.
Chill. Refrigerate the cooled cheesecake for at least 4 hours, ideally overnight.
Top and serve. Run a thin knife around the edge and release the springform pan. Top with whipped cream (if using), a drizzle of honey, and the chopped walnuts. Slice and serve.