In a large skillet over medium-high heat, cook the bacon until crisp. Transfer to a paper towel-lined plate and set aside.
In the same skillet, melt the butter. Place two slices of bread in the skillet and top each slice with one slice of cheese. Top each slice of cheese with some of the cooked bacon and jalapeno.
Top each sandwich with the remaining two slices of bread. Cook for 3 minutes or until lightly browned on one side. Flip over and cook for another 3 minutes or until lightly browned on the other side.