Preheat your oven to 325°F and grease a 9-inch springform pan.
In a large bowl, whisk together the ricotta, butter, and sweetener until smooth.
Add the eggs one at a time, whisking well after each addition.
Stir in the vanilla extract.
In a separate bowl, whisk together the almond flour, cocoa powder, baking powder, and salt.
Add the dry ingredients to the wet mixture and stir until fully combined.
Pour the batter into the prepared pan and smooth the top.
Bake for 40–45 minutes, until the edges are set and the center has a slight jiggle.
Let the cake cool in the pan, then refrigerate for at least 2 hours before slicing.