A cup of good Earl Grey tea has a tantalizing flavor. The background tastes of heady, earthy, slightly astringent black tea, but it's lifted up by bergamot, which to me always tastes like a mix of citrus; at times the best parts of orange, lemon, and grapefruit. I drink Earl Grey almost every day, and over a recent cup I decided to use it in my baked goods rather than alongside it.
The trick to getting good tea flavor into your dough is two fold. First, I've found that better quality loose leaf tea—the kind that actually looks like dried up tea leaves, not ground dust—is important. Look for a blend that has a full, citrusy flavor when brewed. The second trick is to steep the tea in milk that stays warm. I put the milk over low heat in a small saucepan and, when it's warm, add the tea leaves and cover the pot. I check the temperature halfway through steeping time—if it's getting cold, I put the heat back up until it's warm.
To play up the two sides of Earl Grey flavor (citrusy/earthy), I also added fresh lemon zest and just a pinch of nutmeg. To really put this morning muffin over the top, I suggest you serve it warm, spread it with some chunky English marmalade. It will be sweet and citrusy all around.