Combine bacon, cheddar, mayonnaise, jalapeños and cream cheese together in a bowl. Mix well.
To assemble sandwich: spread butter on one side of each slice of bread. Spread 1/4 of the mixture on the non-buttered side. Top with another slice of bread. Repeat until 4 sandwiches are made.
Heat a skillet over medium high heat and cook sandwiches until bread is golden brown and cheese has melted, about 3 minutes per side. Serve.