Make cookies. Prepare and roll out cookie dough following recipe directions. Use knife to cut squares, 3 1/2 in. x 3 1/2 in. Bake and cool cookies.
Cover cookies. Prepare royal icing following recipe directions. Tint portions black and sky blue; reserve remaining white. Place cookies on cooling grid over cookie sheet. Cover cookies with thinned black icing. Let dry overnight.
1 DAY IN ADVANCE
Decorate cookies. Use tip 2 and thinned white icing to pipe horizontal and vertical lines. Use tip 1 and thinned blue icing to pipe horizontal and vertical lines. Let dry.
Make fondant initial. Tint a 1 1/8 in. ball of white fondant per treat sky blue. Press blue fondant in letters/numbers fondant and gum paste mold to make desired initials. Use icing to attach to cookies.