Heat a large skillet over medium-high heat. Add your 1 lb (450g) of bulk breakfast sausage, breaking it apart with a wooden spoon as it cooks. Sizzle the meat until the fat renders out and the crumbles turn a deep, caramelized brown—about 6 to 8 minutes. Once fully browned, use a slotted spoon to transfer the crumbled pieces to a paper towel-lined plate. Allow the meat to drain and cool completely.

Preheat your oven to 425°F (220°C). Generously grease your dark metal muffin tin with non-stick spray or melted butter to ensure those crispy edges easily release.

In a large mixing bowl, thoroughly whisk together the 2.5 cups (315g) flour, 1 tbsp (15g) baking powder, 0.5 tsp (3g) baking soda, and 1 tsp (6g) kosher salt.

In a separate medium bowl, whisk the 2 large room-temperature eggs until light and slightly frothy. Slowly pour in the 1.5 cups (360ml) buttermilk and 0.5 cup (113g) cooled melted butter, whisking vigorously until cohesive.

Create a well in the center of your dry ingredients and pour the liquid mixture directly into it. Using a silicone spatula, gently fold the batter together using broad, sweeping motions. Stop folding when there are still a few flour streaks remaining.

Gently dump the cooled crumbled sausage, the 1.5 cups (170g) cheddar cheese, and the 1/4 cup (12g) chopped green chives into the bowl. Fold them into the batter with 4 or 5 gentle stirs. Scoop the batter into the prepared muffin tin, filling each cavity all the way to the top.

Place the tin into the preheated 425°F (220°C) oven and bake for exactly 5 minutes. Without opening the oven door, drop the temperature down to 375°F (190°C) and bake for an additional 12 to 15 minutes. They are done when the edges are crispy and a toothpick comes out clean.