For the blondies:
1 cup packed dark or light brown sugar
6 tablespoons butter
1 teaspoon vanilla
1 egg
1 cup all-purpose flour
1/2 teaspoon baking powder
For the frosting:
2 tablespoons milk
1 teabag Earl Grey or Chai tea, or 1 teaspoon leaves
1/4 cup unsalted butter, softened
1 cup powdered sugar