Prep your gear. Line a mini muffin pan with paper liners or set out a silicone candy mold. This recipe makes about 12–16 fat bombs depending on size.
Warm the base. In a small saucepan over low heat, add peanut butter, coconut oil, and butter.
Stir until fully melted and smooth, about 2–3 minutes. Don’t let it simmer.
Sweeten and flavor. Remove from heat. Whisk in the powdered sweetener, vanilla, and salt.
Taste and adjust sweetness. If using cocoa or cinnamon, whisk it in now.
Thicken if needed. If the mixture seems too thin, let it cool for 3–5 minutes so it slightly thickens. This helps it set evenly in the molds.
Fill the molds. Pour or spoon the mixture into the liners.
If using crushed peanuts, sprinkle a bit on top and gently press so they stick.
Chill to set. Freeze for 20–30 minutes until firm. Pop the fat bombs out and transfer to an airtight container.
Enjoy. Store in the fridge and eat straight from cold for the best texture.