Pre heat the broiler to high. Grease a muffin pan.
Chop bacon into 1-inch pieces. Add to a skillet and cook over medium heat until about halfway done. Remove and place on a paper towel.
Place 1 crumbled Ritz cracker on the bottom of each muffin. Sprinkle the tops with pepper jack cheese (about 1 to 1 ½ cups). Top with the bacon followed by an oyster and 1 -2 jalapeno slices.
Broil for about 5 to 6 minutes or until the oysters puff up slightly, and are crisp and brown. Remove from the oven and sprinkle with the remaining cheese (about ½ cup). Return to the oven and continue baking just until the cheese is melted. Serve hot.