Preheat your oven to 350°F (175°C).
Grease your 9-inch cake pan with butter or non-stick spray and line the bottom with parchment paper.
In a large mixing bowl, beat together the softened unsalted butter and granulated sugar until light and fluffy, about 3-4 minutes.
Add the ricotta cheese, eggs, and vanilla extract to the butter mixture. Beat until smooth.
Zest the lemon and add both the zest and the juice to the batter, mixing until fully incorporated.
In a separate bowl, whisk together the baking soda, salt, and all-purpose flour.
Gradually add the dry ingredients to the wet mixture, folding gently with a rubber spatula.
Pour the cake batter into the prepared cake pan, smoothing the top.
Bake for approximately 45-50 minutes, or until a toothpick inserted into the center comes out clean.
Allow the cake to cool in the pan for about 10 minutes, then transfer to a cooling rack to cool completely.
Dust the top with powdered sugar before serving.