Heat a large skillet over medium-high heat. Spread butter onto one side of each slice of bread. Place up to 4 of the slices of bread, butter side down in the skillet. Top each piece with one slice of cheese, two slices of ham, and about 2 tablespoons of the crushed pineapple. Place remaining slices of bread on top with the butter side up. When the bottom of the sandwich is golden brown, flip sandwiches, and cook until browned on the other side, about 1 minute. Repeat steps with remaining ingredients if all four sandwiches do not fit in your skillet.