In a large bowl, whisk together the almond flour, powdered sweetener, cocoa powder, and salt until well combined. This forms the perfect dry foundation for your delicious truffles.
Gently stir in the melted butter and vanilla extract until a cohesive dough begins to form. If the mixture seems too crumbly to roll, add water one tablespoon at a time, mixing thoroughly after each addition, until it's easy to shape.
Roll the mixture into delightful 1-inch balls and arrange them on a baking sheet lined with waxed paper. Place these in the freezer for at least one hour to allow them to firm up perfectly.
While your truffles are chilling, prepare the chocolate coating. Set a heatproof bowl over a pan of barely simmering water (creating a double boiler effect). Add the chopped sugar-free dark chocolate and cocoa butter (or coconut oil), stirring until it's completely smooth and melted.
Take the frozen truffle balls and, one by one, carefully drop them into the warm melted chocolate, tossing to coat them completely. Lift each truffle out with a fork, allowing any excess chocolate to drip off, then place it back on the waxed paper. If you're adding any sprinkles or decorations, do it immediately before the chocolate sets!
Allow the chocolate coating to fully harden, either at room temperature or in the refrigerator. Once set, these no-bake, healthy brownie batter truffles are ready for you to enjoy guilt-free!