01 - Heat the milk in a small saucepan until steaming without boiling. Add the Earl Grey tea bags and 2 tsp lavender; steep for 15 minutes. Remove tea bags, strain out lavender, and let cool completely. Reserve 2–3 tbsp of the infused milk for the frosting; use the remainder for the cake batter.
02 - Preheat oven to 350°F. Grease and line two 8-inch round cake pans. Whisk together flour, baking powder, baking soda, and salt in a bowl. In a large bowl, cream butter and sugar until light and fluffy. Beat in eggs one at a time, then add vanilla. Alternately add the flour mixture and infused milk, beginning and ending with flour, mixing just until combined. Divide batter evenly between pans. Bake 25–30 minutes, or until a toothpick comes out clean. Cool 10 minutes in pans, then transfer to a rack to cool completely.
03 - Combine water, sugar, and lavender in a small saucepan. Bring to a simmer, stirring until sugar dissolves. Remove from heat; steep 10 minutes, strain, and cool to room temperature.
04 - Beat butter on medium-high speed until creamy. Gradually add powdered sugar, then vanilla and salt. Beat in reserved infused milk, 1 tbsp at a time, until desired consistency is reached.
05 - Brush cooled cake layers with lavender syrup. Place one cake layer on a serving plate, spread with frosting. Top with second layer, frost top and sides. Garnish with additional dried lavender if desired.