Thoroughly butter one side of each slice of bread. Set aside.
Combine the ground beef, pepper, salt, and onion powder in a bowl and mix until the spices are evenly distributed.
Shape the mixture into three separate patties to match the shape of the bread.
Preheat a nonstick skillet on the stove over medium-high heat.
Place the patties in the skillet and cook for approximately 2-3 minutes. Then, flip them carefully to avoid breaking, and cook them for another 2-3 minutes on the other side.
Reduce to low heat and cook for approximately 5 more minutes. The centers should be uniformly brown with no pink remaining.
Use a digital thermometer to check the internal temperature of each patty. Each one should be 160 degrees Fahrenheit (71°C).
While the patties cook, mix the mayo, ketchup, bacon bits, relish, and sugar in a small bowl. Stir until well-blended, and set aside.
When the patties are ready, heat a second skillet on medium-low heat, and add one slice of bread (butter-side down) – or as many will fit.
Top the bread with two slices of cheddar cheese, followed by a patty and two slices of Provolone.
Spread the sauce over the unbuttered side of the second bread slice. Then, place that piece of bread (sauce-side down) on top of the last slice of cheese.
Cook for 2-3 minutes on each side or until the bread is lightly toasted.
Repeat steps 6, 7, and 8 until all three patty melts are ready.
