Preheat your oven to 350°F (175°C). Grease an 8x8-inch baking pan or line it with parchment paper for easy removal.

In a large mixing bowl, whisk together the cocoa powder, almond flour, sea salt, baking powder, and zero-calorie sweetener until well combined.

In a separate bowl, mix the Greek yogurt, eggs, vanilla extract, and applesauce until smooth.

Pour the wet ingredients into the dry ingredients, and stir until just combined, being careful not to overmix.

Transfer the batter to the prepared baking pan, spreading it evenly with a spatula.

Bake for 25-30 minutes, or until a toothpick inserted into the center comes out with a few moist crumbs.

Allow the brownies to cool in the pan for about 10 minutes, then lift them out using the parchment paper (if used) and let them cool completely on a wire rack before cutting into squares.