Spray a grill pan with nonstick spray and place over medium-high heat on the stove.
Lay bread slices on a flat surface, and evenly spread the cheese wedge onto one slice of bread. Slice red pepper into strips, and evenly place over the slice of bread spread with cheese. Top with the slice of cheese, followed by the other slice of bread.
Spread 1/2 tablespoon of butter onto the upward-facing slice of bread. Sprinkle with a dash of garlic powder.
Gently place the sandwich in the hot grill pan with the buttered side down. Carefully spread the remaining 1/2 tablespoon of butter onto the upward-facing side. Sprinkle with the remaining dash of garlic powder.
Cook until the cheese has melted and the bread is lightly browned, 1 to 2 minutes per side, flipping carefully. Eat your sandwich and enjoy it!