01 -
Add the bacon in a single layer to a non-stick skillet and heat over medium heat. Cook until crispy, turning as needed. Remove from the pan and drain on a paper towel-lined plate.
02 -
In a small bowl, combine the cream cheese, Cheddar, Monterey Jack, chopped jalapeños, and cumin (if using). Mix well. Once the bacon has cooled, chop it and add it to the cheese mixture.
03 -
Butter one side of each slice of sourdough bread. Spread the filling evenly on 2 slices, then top with the remaining slices, buttered sides facing outwards.
04 -
Drain off the bacon fat from the skillet and wipe it clean with a dry paper towel. Heat the skillet over medium heat. Sprinkle Parmesan cheese on the top side of each sandwich, if using, and place them Parmesan side down in the skillet. Sprinkle Parmesan on the other sides as well. Cook, uncovered, until golden brown, then flip and cook until golden on the other side.
05 -
Remove the sandwiches from the skillet and let them cool for a few minutes. Slice with a serrated knife and serve immediately. The filling can be prepared in advance and stored in the refrigerator for up to 3 days. Allow it to come to room temperature before using.