Heat milk in a small saucepan and steep Earl Grey tea for 10 minutes, then cool.
Cream butter and sugar until light and fluffy.
Add eggs one at a time, mixing well, then stir in vanilla and lemon zest.
Whisk flour, baking powder, and salt in another bowl.
Add dry ingredients to the wet mixture alternately with the cooled tea-infused milk.
Spoon batter into lined muffin tins, filling 66 percent full.
Bake at 350°F for 16–18 minutes until golden.
Cool on a wire rack and dust with powdered sugar before serving.