Homemade biscuits on a baking tray
Mayonnaise Is The Creamy Shortcut Your Homemade Biscuits Need

If you use mayonnaise to make a biscuit batter, the only other ingredients you’ll need are milk and self-rising flour, and the result will be perfectly moist and tender biscuits.

Since mayo’s main components are eggs and oil, both of which are used to add moisture and structure to biscuits, using it in biscuit batters eliminates the need to add eggs or oil.

Plus, mayo's acidity, which comes from the vinegar or lemon juice in it, makes it act like buttermilk, a fatty, mildly acidic dairy product used to make biscuits fluffy and tender.

Thus, mayo provides the fat and acid needed to make biscuits soft and keeps the ingredients list short, leaving you with enough time to make a dish you can serve with the biscuits.