Mix the PB layerIn a small bowl, stir peanut butter and maple syrup until smooth and creamy. Set aside.
Melt the dark chocolateMelt dark chocolate chips with coconut butter in the microwave in 20–30 second intervals, stirring until smooth.
Create the baseLine a mini muffin tin with paper liners. Spoon about 1 tablespoon of the dark chocolate mixture into each cup. Gently tap the pan to spread evenly.Freeze for 5–7 minutes, just until set.
Add the PB layerSpoon a small dollop (about 1–2 teaspoons) of the maple PB mixture onto each chocolate base. Gently flatten.
Top with milk chocolateMelt milk chocolate chips and spoon over the PB layer, fully covering it.
Finish & setSprinkle lightly with flaky sea salt.Refrigerate or freeze until firm (about 20–30 minutes).