Use a 5"X5" piece of baking paper if you don't have muffin liners. Quick and easy release, you don't have to grease with butter & they look so pretty too : r/foodhacks
How To Make Parchment Baking Liners - Gimme Some Oven
How to Make Muffin Liners out of Parchment Paper (with Video!) - Sugar Spun Run
How to Make Muffin Liners out of Parchment Paper (with Video!) - Sugar Spun Run
How to use cupcake and muffin papers | King Arthur Baking