Begin by preheating your oven to 375°F (190°C). While the oven heats, line a large baking sheet with parchment paper. This step is crucial for preventing sticking and ensures easy cleanup after baking. Using parchment paper also helps the sausage balls to brown evenly.

In a large mixing bowl, combine the softened cream cheese with the undrained can of Rotel Diced Tomatoes with Green Chilies. Use a sturdy spoon or a rubber spatula to mix them thoroughly until well combined. The texture should be relatively smooth, with the tomatoes evenly distributed throughout the cream cheese. This forms the creamy, tangy core of your sausage balls.

Next, crumble the raw breakfast sausage into the cream cheese and Rotel mixture. Add in the optional garlic powder and black pepper at this stage. Using your hands, mix everything together. It's important to really get your hands in there and combine until the sausage is evenly distributed and the mixture is uniform. This process can be a bit messy but is essential for ensuring every bite is flavorful.

Once the sausage mixture is well combined, gradually add the Bisquick baking mix and the shredded cheddar cheese. Continue mixing with your hands until all the dry ingredients are fully incorporated into the wet mixture. The dough will become quite stiff, but it should still be pliable enough to roll. Be careful not to overmix, which can lead to tough sausage balls. If using, fold in the thinly sliced green onions at this point for an added layer of flavor and color.

Scoop small portions of the mixture, about 1 to 1.5 tablespoons each, and roll them into uniform balls. Aim for a size similar to a golf ball for even cooking. Place the formed balls on the prepared baking sheet, leaving about an inch of space between each to allow for even air circulation and browning.

Transfer the baking sheet to your preheated oven and bake for 20-25 minutes. The baking time may vary slightly depending on your oven and the size of your balls. They are done when they are golden brown on the outside and cooked through in the center. To check for doneness, you can break one open; the sausage should no longer be pink.

Once baked, remove the sausage balls from the oven and let them cool on the baking sheet for a few minutes before transferring them to a serving platter. They are best served warm, allowing the cheesy, creamy interior to shine through. Enjoy them on their own or with your favorite dipping sauce!