In a large bowl, combine the flour, powdered sweetener (if using powdered), baking powder, and salt. In a separate bowl, combine the almond milk, melted butter, eggs, extract, and liquid sweetener (if using liquid). Stir the wet mixture into the dry mixture.
Grease a large skillet with coconut oil and place it over medium-high heat. Pour 3 tablespoons of the batter into the hot skillet, making a circle about 3½ inches in diameter. Cook the pancakes until the bottoms are golden brown, about 2 minutes, then carefully flip and cook on the other side until golden. Repeat with the remaining batter, greasing the pan as needed between batches.
Make the sauce:
Before you begin, make sure you have the sweetener, cashew milk, and extract next to the pan, ready to go in. Work fast or the sweetener will burn. Heat the butter in a heavy- bottomed saucepan over high heat. As soon as it comes to a boil, watch for brown flecks; this is browned butter (so good on veggies!). Immediately add the sweetener, milk, and extract to the pan. Whisk until the sauce is smooth, then slide the pan off the heat. (Note: The sauce can be made up to 2 weeks ahead.)
To serve, place 2 pancakes on each plate and top with walnuts, Brie, and sauce. Enjoy!