Preheat the oven to 180°C.
Steep an Earl Grey tea bag in milk for 10 minutes.
Cream butter and sugar together in a bowl.
Add eggs and mix well.
Add the steeped milk (remove the tea bag) and mix.
Sift in cake flour, baking powder, and salt, then mix until combined.
Divide the batter evenly into muffin tins.
Bake in a 180°C oven for 20–25 minutes.