Mix the raspberries, sugar, and lemon juice in a small saucepan over medium heat. Stir to coat the berries in sugar.
Cook while frequently stirring until the mixture starts to boil.
Reduce the heat to medium-low and simmer while occasionally stirring for 10-12 minutes or until thickened enough to leave a trail when you run a spoon through the jelly.
Remove from the heat, transfer the jelly to a jar, and set it aside to cool.
Add the peanuts, oil, maple syrup, and salt to a blender.
Blend until smooth and creamy. Occasionally stop to scrape the sides down for an even consistency.
Spoon the peanut butter out of the blender and into a bowl or jar.
Spread four of the eight slices of bread with peanut butter. Spread the other four slices of bread with raspberry jelly.
Put the two pieces of bread together to form sandwiches, then brush the exterior of each sandwich with melted butter.
Preheat your Z-Grill (preferably with branded applewood pellets) or other wood pellet grill to 350 degrees Fahrenheit.
Place the grill mat on the grates and transfer the sandwiches to the grill mat.
Close the lid and grill for 4-5 minutes.
Open the lid, flip the sandwiches, close, and grill for another 4-5 minutes.
Plate the grilled peanut butter and jelly sandwiches, then serve.