Preheat the Oven: Preheat your oven to 400°F (200°C) and line a muffin tin with paper liners or grease it lightly.
Mix Dry Ingredients: In a large bowl, whisk together the flour, baking powder, sugar, and salt until well combined.
Combine Wet Ingredients: In a different bowl, combine the milk, egg, and melted butter. Whisk until smooth.
Combine Mixtures: Pour the wet ingredients into the dry ingredients and stir gently until just combined. Be careful not to overmix; a few lumps are okay!
Fold in Sausage: Gently fold in the chopped sausage, ensuring even distribution throughout the batter.
Fill Muffin Tin: Scoop the batter into the prepared muffin tin, filling each cup about three-quarters full.
Bake: Place the muffin tin in the preheated oven and bake for 15-18 minutes, or until the muffins are golden-brown and a toothpick inserted in the center comes out clean.
Cool and Serve: After baking, let the muffins cool for a few minutes in the tin before transferring them to a wire rack. Serve warm and enjoy!