01 -
Line the bottom and sides of a 6 or 8-quart slow cooker with a large piece of aluminum foil and spray with nonstick cooking spray.
02 -
In a large bowl, whisk together milk, beaten eggs, granulated sugar, one packet of au jus gravy mix, one packet of ranch seasoning mix, and panko breadcrumbs until fully combined.
03 -
Add the ground beef to the bowl and gently mix with clean hands until just combined. Avoid overmixing to prevent toughness.
04 -
Transfer the meat mixture to the slow cooker and shape into an oval.
05 -
In a separate container, whisk together cold water, peperoncini juice, remaining packets of au jus gravy mix, and ranch seasoning mix until well combined.
06 -
Pour the gravy mixture evenly over and around the meatloaf. Arrange the peperoncini peppers on top.
07 -
Cover and cook on low for 5 to 6 hours or on high for 3 to 4 hours, until the internal temperature reaches 165°F.
08 -
Carefully lift the meatloaf out using two spatulas and transfer to a serving dish.
09 -
Strain cooking juices into a medium saucepan and heat over medium. Whisk cornstarch with water until smooth, then gradually add to simmering gravy while whisking continuously. Cook for one minute until thickened, then remove from heat.
10 -
Slice meatloaf and serve with additional gravy poured over each portion.