Step 1: Preheat your oven to 325°F (165°C) and grease a 9×5 inch loaf pan, lining the bottom with parchment paper.
Step 2: In a small saucepan, gently heat the milk and 1 teaspoon of the ground Earl Grey tea leaves until warm. Remove from heat and let steep for 10 minutes.
Step 3: In a medium bowl, whisk together the flour, the remaining ground tea leaves, baking powder, and salt.
Step 4: Using a stand mixer or hand mixer, cream the softened butter and sugar together on medium-high speed until light and fluffy (about 3-5 minutes).
Step 5: Add the eggs one at a time, beating well after each addition and scraping down the sides of the bowl.
Step 6: Stir in the vanilla extract to the butter mixture.
Step 7: Gradually add the dry ingredients to the wet ingredients in three parts, alternating with the infused milk, beginning and ending with the flour mixture.
Step 8: Pour the batter into the prepared loaf pan and smooth the top with a spatula.
Step 9: Bake for 55-65 minutes, or until a toothpick inserted into the center comes out clean.
Step 10: Allow the cake to cool in the pan for 10 minutes before transferring to a wire rack to cool completely.