Preheat the oven to 180C / 350 F and line a 10 cup muffin pan with paper liners.
In a mixing bowl, whisk flour and sugar (if using).
2 cup self-rising flour, 1 teaspoon sugar
Mix in milk and mayonnaise until well combined.
1 cup whole milk, ¼ cup mayonnaise
Scoop the batter into the muffin cups.
Bake for 12-15 minutes, then let them cool.
Notes
Do not overfill the paper liners with the batter because it will spill once the batter rises inside the oven.
I like to grease the paper liners with butter or spry with oil before filling them with the batter so that I can easily remove them once the baking process is done.