1Heat oven to 350°F. Place mini paper baking cup in each of 60 mini muffin cups; spray paper cups with cooking spray.
2In large bowl, beat butter and cream cheese with electric mixer on medium speed 2 minutes or until light and fluffy. Gradually add granulated sugar, beating until blended. Beat on medium speed 5 minutes. Add eggs, one at a time, beating just until blended after each addition. On low speed, beat in flour and salt until smooth. Beat in lemon peel and juice. Divide batter evenly among muffin cups.
3Bake 15 to 17 minutes or until toothpick inserted in center comes out clean. Cool 10 minutes; remove from pans to cooling racks. Cool completely. Sprinkle cakes with powdered sugar before serving.