Preheat oven to 350 degrees. Grease or line a 12 cup muffin tin with cooking spray or cupcake liners; set aside.
In a large bowl, whisk together the milk, eggs, sugar, oil, and vanilla. Add in the pancake mix and just combined.
Fold in whatever mix ins you are using. Scoop the batter into the prepared muffin tin using a muffin scoop.
Bake in preheated oven for about 20-22 minutes, or until a toothpick inserted into the muffins comes out clean. Let cool on rack for 5 minutes, then remove from pan and let cool completely.
Notes
Pancake Mix: use your favorite store-bought or homemade pancake mix for this recipe. I have tried it with both with great results.
Milk: you can use whatever milk you have on hand. This works with almond milk, oat milk, or regular milk.
Mix Ins: use your favorite mix in here such as chocolate chips, blueberries, bananas, coconut, or strawberries. You can also sprinkle the toppings on top and stir them into the muffin batter in the tin.
Storage: store leftover muffins in an airtight container in the refrigerator for up to a week. You can also freeze muffins in an airtight container for a month.