To make cream-cheese icing, beat 8 ounces cream cheese, 1/2 cup unsalted butter and 1 teaspoon vanilla extract in an electric mixer until smooth. Add 3 1/2 cups confectioners' sugar, and mix until light and fluffy.
For a coconut cream-cheese variation, combine 8 ounces cream cheese and 1/2 cup unsalted butter in a mixing bowl. Beat until light and fluffy. Add 4 cups confectioners' sugar, 1 cup at a time, alternating with 2 tablespoons heavy cream. Mix in 1/2 teaspoon salt, 1/2 teaspoon coconut flavoring and 1 teaspoon vanilla extract, beating until mixture is smooth and creamy. If the mixture is too thick, add more cream; if it is too thin, add more confectioners' sugar. Gently add 1/2 cup sweetened shredded coconut. If desired, spread 1 cup toasted shredded coconut as garnish.
To make strawberry cream-cheese icing, blend 8 ounces cream cheese with 1/4 cup butter on low speed until well mixed. Gradually add 3 cups sifted confectioners' sugar and 1/2 cup mashed drained fresh strawberries (about 3/4 cup hulled fresh strawberries). Blend until mixed, about one minute. Adjust mixer to medium speed, and blend icing until fluffy, adding up to 1/2 cup confectioners' sugar as desired to reach the correct consistency.