Preheat the oven to 350°F (175°C).
Grease and flour an 8-inch round cake pan.
In a mixing bowl, combine ricotta cheese and sugar.
Add eggs one at a time, mixing well after each addition.
Stir in vanilla extract.
In a separate bowl, whisk together flour, cocoa powder, baking powder, and salt.
Gradually add the dry ingredients to the ricotta mixture and mix until just combined.
Fold in chocolate chips if using.
Pour the batter into the prepared pan and smooth the top.
Bake for 30-35 minutes or until a toothpick inserted comes out clean.
Let the cake cool in the pan for 10 minutes, then transfer to a wire rack to cool completely.
Serve plain or with whipped cream and fresh berries.
