Step 1: Cook the Sausage
Heat a skillet over medium-high heat and cook the sausage until fully browned, breaking it into small crumbles as it cooks. Drain off any excess grease to keep the muffins light and not oily.
Step 2: Prepare the Batter
Preheat the oven to 350°F (175°C). In a large mixing bowl, whisk together the eggs, shredded cheddar cheese, and Bisquick until smooth and well combined.
Step 3: Combine and Fill
Fold the cooked sausage gently into the batter. Lightly grease a 12-cup muffin tin or line with paper liners. Fill each muffin cup about three-quarters full to allow room for rising.
Step 4: Bake and Cool
Bake for 18–20 minutes, or until the tops are golden and a toothpick inserted into the center comes out clean. Let the muffins cool in the pan for 2–3 minutes before removing and serving.