Brown the ground beef in a skillet over medium-high heat, breaking it into small pieces as it cooks, then drain the fat completely.
Cut the Velveeta cheese into 1-inch cubes for easier melting.
Add the cubed Velveeta, both cans of Rotel with their liquid, cooked ground beef, garlic powder, and cumin to the slow cooker.
Cover and cook on low for 1 hour, stirring every 20 minutes until the cheese is completely melted and smooth.
Keep on the warm setting during your party, stirring occasionally, and garnish with fresh cilantro if desired.
Serve with tortilla chips, corn chips, or soft pretzel bites.