Toast the nuts by placing them in a pan on the stove at low to medium heat. Toast them for about 5 minutes until they are fragrant (stirring frequently). Place the nuts and salt in a food processor and grind to a fine powder. Add maple syrup and butter and process until it becomes smooth. If you like chunky peanut butter you can process the nuts for a shorter time. Store in an airtight container in the refrigerator. Serve this at room temperature.