Step 1: Add the pork to the slow cooker - Place the pork tenderloins directly into the slow cooker spreading them out so they cook evenly.
Step 2: Make the sauce - In a small bowl whisk together the bbq sauce Dr. Pepper brown sugar and onion powder until smooth.
Step 3: Pour and cook - Pour the sauce over the pork making sure it is well coated. Cover and cook on low for 6 hours or high for 4 hours until the pork is tender and easy to shred.
Step 4: Boil the pasta - About 20 minutes before serving cook the elbow macaroni according to package directions. Drain and set aside.
Step 5: Make the roux - In a large saucepan over medium heat melt the butter. Whisk in the flour and salt and cook for about one minute until smooth.
Step 6: Add the milk - Slowly whisk in the warmed milk and bring the mixture to a gentle bubble stirring constantly until thickened.
Step 7: Add the cheese - Stir in the shredded sharp cheddar cheese until melted and smooth.
Step 8: Combine with pasta - Gently stir the drained macaroni into the cheese sauce until fully coated.
Step 9: Shred the pork - Remove the pork from the slow cooker and shred it using two forks. Stir it back into the sauce if desired.
Step 10: Assemble the sliders - Place a generous amount of pulled pork onto each slider bun add a slice of cheddar cheese then top with a scoop of mac and cheese. Serve warm and enjoy.