Grease a small microwave-safe ramekin or mug with butter or cooking spray.

Add the almond flour, baking powder, and salt to the ramekin and stir to combine.

Add the egg and melted butter, then whisk everything together with a fork until completely smooth with no lumps.

Microwave on high for 90 seconds, then let cool for 1 minute before running a knife around the edges and turning out onto a plate.

Slice horizontally and toast in a toaster or skillet for best texture and flavor.