Preheat your oven to 350 degrees Fahrenheit and prepare an 8-inch by 8-inch square pan by greasing it and lining the bottom and 2 sides with parchment paper.
To a large bowl add the melted butter, Stevia brown sugar, eggs, and vanilla. Whisk them together until the mixture is smooth and all the ingredients are well combined.
Place a fine mesh sieve over the bowl with the wet ingredients and add the almond flour to it, along with the cocoa powder, espresso powder, and salt.
Push the dry ingredients through the sieve with a spoon. This will leave any large chunks behind (discard these).
Combine the wet and dry ingredients with a silicone spatula or wooden spoon until well mixed and no streaks of flour remain.
Pour the batter into the prepared baking pan and spread it out into the corners of the pan, smoothing out the top.
Bake for about 16-18 minutes at 350 degrees Fahrenheit.
Let the brownies cool completely in their pan before slicing and enjoying.
Using Stevia brown sugar in this recipe helps give these brownies their ultra-moist texture. You can replace the Stevia brown sugar with regular baking stevia and still achieve good results with this recipe.