HEAT oven to 350ºF.
BEAT first 5 ingredients in large bowl with mixer until blended. (Batter will be thick.) Spoon into 24 paper-lined muffin cups.
BAKE 21 to 24 min. or until toothpick inserted in centers comes out clean. Cool in pans 10 min. Remove to wire racks; cool completely.
BEAT cream cheese, butter and lemon juice in large bowl with mixer until blended. Gradually beat in sugar until blended. Spread onto cupcakes.