Spread 1 tablespoon of softened butter on one side of each slice of bread.
Place two slices of bread, buttered side down, onto the skillet.
On each slice, layer 2 slices of cheddar cheese, followed by 4 slices of bacon, 2-3 slices of tomato, and a handful of arugula.
Season with salt, pepper, and garlic powder (if using) before topping each sandwich with another slice of cheese.
Top each sandwich with the remaining slices of bread, buttered side up.
Cook for about 4-5 minutes on medium heat until the bottom is golden brown and the cheese starts to melt.
Carefully flip the sandwiches over and cook for an additional 4-5 minutes on the other side until the bread is golden and the cheese is completely melted.
Remove from the skillet and let sit for a minute before slicing in half.
Notes
Serve warm on a rustic board, garnished with extra arugula and tomato slices. Pair with homemade tomato soup for dipping!