Line 8-inch square pan with plastic wrap. In large bowl with electric mixer, beat all cookie ingredients except flour at medium speed, scraping bowl occasionally, until creamy. Reduce speed to low; beat in flour, scraping bowl occasionally, until mixture forms a dough. Press dough firmly and evenly in pan. Refrigerate 30 minutes.
Heat oven to 350°F. Using edges of plastic wrap, lift dough from pan. With sharp knife, cut into 8 rows in each direction to make 64 squares; carefully place squares 1 inch apart on ungreased cookie sheets.
Bake 13 to 17 minutes or until edges are lightly browned. Cool 5 minutes; remove from cookie sheets. Cool completely, about 10 minutes.
In medium bowl, mix all frosting ingredients except food color until smooth, adding enough half-and-half for desired spreading consistency. In small bowl, mix 1/3 cup of the frosting and enough food color until desired color and well blended; place in small resealable food storage plastic bag and partially seal.
Spread uncolored frosting over cooled cookies. Cut small hole in bottom corner of bag of colored frosting. Squeeze bag to pipe frosting onto each cookie to resemble bows.