In a large mixing bowl, combine the softened cream cheese, shredded cheddar cheese, mayonnaise, garlic powder, 1/4 teaspoon of the ground cumin, 1/4 teaspoon of the chili powder, salt, and black pepper. Use an electric mixer to beat on medium speed until the mixture is light, fluffy, and well combined, scraping down the sides of the bowl as needed.

Transfer the cheese mixture onto a piece of plastic wrap. Using the plastic wrap, form the mixture into a log shape, about 6-8 inches long. Wrap it tightly and chill in the refrigerator for at least 30 minutes to firm up.

While the cheese log chills, prepare the cowboy caviar topping. In a separate medium bowl, combine the rinsed and drained black beans, corn, finely diced red bell pepper, finely diced red onion, chopped fresh cilantro, freshly squeezed lime juice, the remaining 1/4 teaspoon ground cumin, and the remaining 1/4 teaspoon chili powder. Stir gently to combine all ingredients.

Once the cheese log is firm, unwrap it and place it on a clean serving platter or a piece of parchment paper. Spread the cowboy caviar mixture evenly onto a shallow dish or plate. Carefully roll the cheese log through the caviar mixture, pressing gently, until it is thoroughly coated on all sides. You may need to use your hands to press any loose pieces onto the log.

Once coated, place the cowboy caviar cheese log back onto a serving platter. Chill for another 15-30 minutes if you have time, allowing the flavors to meld and the log to firm up nicely. Serve immediately with your favorite tortilla chips, crackers, or pita bread.