Preheat oven to 350º F. Line an 8x8 baking dish with parchment paper and set aside.
In a food processor bowl, add the avocado, melted butter, eggs, and vanilla. Process until the avocado is smooth and no chunks remain.
Add the monk fruit sweetener, cocoa powder, almond flour, baking powder, and salt. Pulse to combine until a thick and fudgy batter is formed.
Add batter to the prepared baking pan, and use wet hands or a wet spatula to spread it into an even later. Top with sugar free dark chocolate chips, if desired.
Bake the brownies for 26-30 minutes, until the edges start to pull away from the pan and the center is slightly underbaked.
Allow brownies to fully cool before slicing. Chilling the brownies will make the cleanest cuts. Store leftover brownies in the refrigerator for up to 5 days, or wrapped tight and frozen for up to 3 months.