Preheat the oven to 350°F (175°C) and grease a 9-inch round cake pan.

In a large mixing bowl, combine the ricotta cheese, almond flour, sugar, eggs, lemon juice, lemon zest, baking powder, and salt.

Whisk the ingredients together until well combined and smooth.

Stir in the melted butter until fully incorporated.

Pour the batter into the prepared cake pan and smooth the top.

Bake in the preheated oven for 40-45 minutes, or until a toothpick inserted into the center comes out clean.

Allow the cake to cool in the pan for 10 minutes before transferring to a wire rack to cool completely.

Serve the cake plain or with a dusting of powdered sugar.