Preheat your oven: Preheat the oven to 350°F . Line a baking sheet with parchment paper and lightly grease it with cooking spray.
In a large mixing bowl, combine ground beef, shredded cheddar cheese, Bisquick baking mix, taco seasoning mix, diced green onions, sour cream, salsa, and the beaten egg. Mix until all ingredients are well combined.
Scoop out about a tablespoon of the mixture and roll it into a ball using your hands. Place the formed balls onto the prepared baking sheet, leaving some space between each ball.
Bake in the preheated oven for 18-20 minutes or until the taco balls are golden brown and cooked through.