Preheat oven and grease pan:

Heat oven to 350°F (175°C). Coat a 24-cup mini muffin tin with cooking spray or use a paper towel to lightly oil each cup; mini paper liners are also an option.

Brown and crumble sausage:

If using sausage links or patties, remove casings if required. Put sausage in a skillet over medium heat. Break it into small bits using a spatula or wooden spoon while cooking. Stir often until browned evenly on all sides, 6–8 minutes, until no pink remains. Blot excess grease with paper towels; let cool slightly.

Whisk wet ingredients:

In a medium bowl, beat together milk, egg, maple syrup (if using), and vegetable oil or melted butter until smooth.

Mix batter gently:

Pour pancake mix into the wet mixture. Fold gently with a spatula or spoon until no large lumps remain; avoid overmixing (batter should be slightly lumpy, like muffin batter).

Fold in sausage and cheese:

Fold in cooled crumbled sausage and shredded cheddar cheese (if using) until evenly dispersed. Batter will be thick.

Fill muffin cups:

Using a small cookie scoop or spoon, divide batter evenly among the mini muffin cups, filling each about 3/4 full.

Bake until golden:

Bake on the center rack for 12–15 minutes, until tops are golden brown and a toothpick inserted into the center comes out clean or with a few moist crumbs.

Cool and remove from pan:

Let cool in the pan for 5 minutes, then run a butter knife around the edges to loosen and lift out. Transfer to a wire rack to cool completely or serve warm.