Preheat your oven to 375°F (190°C).
In a medium bowl, whisk together the flour, baking powder, sugar, and salt.
Add the milk and mayonnaise. Stir until just combined—don’t overmix.
Grease a muffin tin and spoon the batter evenly into 10–12 cups.
Bake for 15–20 minutes or until the tops are lightly golden.
Let cool for a few minutes, then serve warm with butter or jam (or both).