Preheat your oven to 350°F (175°C). Grease an 8-inch round cake pan and line the bottom with parchment paper.

In a large mixing bowl, whisk together Greek yogurt, eggs, sweetener, coconut oil or butter, and vanilla extract until smooth.

Add almond flour, cocoa powder, baking powder, and salt to the wet mixture. Stir gently until fully incorporated.

(Optional) Fold in dark chocolate chips into the batter gently.

Pour the batter into the prepared cake pan and smooth the top with a spatula.

Bake for 30-35 minutes, or until a toothpick comes out with a few moist crumbs.

Allow the cake to cool in the pan for 15 minutes, then transfer to a wire rack to cool completely.