Preheat your oven to 350 F. Grease a 9-inch round cake pan and line the bottom with parchment paper.
In a large bowl, whisk together the ricotta cheese, eggs, and granulated erythritol until smooth. Stir in the lemon zest and lemon juice.
Add the almond flour, baking powder, and sea salt. Fold gently until just combined. The batter will be thick but pourable.
Pour the batter into the prepared pan and smooth the top.
Bake for 30 to 35 minutes until the cake is golden on top and a toothpick inserted in the center comes out clean. The edges will pull away slightly from the pan.
Let cool in the pan for 15 minutes, then turn out onto a wire rack. Once fully cooled, dust with powdered erythritol and slice to serve.
