Wash the jalapeños thoroughly and slice them in half lengthwise. Using a spoon, carefully remove the seeds and veins from each jalapeño half to reduce the heat. Set the cleaned jalapeños aside.
Take the softened cream cheese and fill each jalapeño half generously. You can use a spoon or a piping bag for this step. Ensure that each jalapeño half is evenly filled with cream cheese.
Slice each tenderloin into eight strips, making a total of 16 strips. Take each strip of tenderloin and lay it on top of a cream cheese-filled jalapeño half. Wrap each jalapeño-tenderloin stack with a slice of bacon, securing it in place.
Sprinkle the BBQ rub (Cow Cover or your preferred brand) evenly over each bacon-wrapped popper, covering them completely. Gently press the rub into the bacon for better adhesion.
Heat grill to a temperature of 275 degrees F (135 degrees C).
Place the prepared poppers on the preheated grill. Cook the poppers for about 45 to 60 minutes or until the bacon turns crisp and the tenderloin is cooked to your desired level of doneess. Keep an eye on the poppers during cooking and adjust the grill's heat if necessary to prevent burning.
Once the BBQ Ranch Beef Tenderloin Poppers are done, carefully remove them from the grill using tongs. Arrange the poppers on a serving platter and enjoy them as a delicious appetizer or snack.