1Scrape vanilla bean seeds into microwavable bowl; add beans to bowl, cover beans with 3/4 cup milk. Microwave on High 1 minute or until mixture boils. Let stand 15 minutes. Remove beans. Add remaining milk to warm milk mixture, stir well. Reserve 1/4 cup milk mixture.
2Heat oven to 350°F (325°F for dark or nonstick pans). Place paper baking cup in each of 24 regular-size muffin cups. In medium bowl, mix flour, baking powder and 1/2 teaspoon salt. In large bowl, beat 3/4 cup butter with electric mixer on medium speed 30 seconds. Gradually add sugar, beating after each addition. Beat 2 minutes longer. Add eggs, one at a time, beating well after each addition. Beat 2 minutes longer. Add eggs, one at a time, beating well. On low speed, alternately add flour mixture and milk mixture, beating just until blended. Divide batter evenly among muffin cups. Bake 17 to 22 minutes or until toothpick comes out clean. Cool 5 minutes. Remove to cooling racks. Cool completely. in large bowl beat frosting ingredients on low speed until blended, adding 1 tablespoon reserved milk mixture at time. Frost cupcakes.