- Heat oven to 350°F. Line the outside of an 8-inch springform pan with a double layer of aluminum foil. Combine ground nuts, butter, and cinnamon; pat onto bottom and sides of pan. Bake until golden, 10-12 minutes; cool on a wire rack.
- In a food processor fitted with a metal blade, process ricotta until very smooth. Add cream cheese; process until smooth. Add eggs, one at a time, processing until incorporated. Add sugar substitute, soy flour, vanilla and lemon zest. Process until smooth, scraping down sides as needed. Pour filling into cooled crust; smooth top.
- Bake cheesecake in a water bath until puffed and golden and a toothpick inserted 1 inch from center comes out clean, about 1 hour. Cool in oven for 30 minutes. Remove from oven, cool to room temperature on a wire rack, then refrigerate. When well chilled, remove from springform pan, cut into wedges and serve.