Using boxed cake mix gives you a jump-start in making these orange-frosted cookies.
Heat oven to 350 degrees F.
In large bowl, beat butter and sugar until creamy, 2 minutes. Add egg; beat to combine (mixture may appear curdled). Add cake mix, wheat germ, 1 tablespoon rind and 1/4 cup juice; beat until thick but smooth.
Drop batter by heaping tablespoons onto ungreased baking sheets, spacing about 2 inches apart.
Bake in 350 degree oven until puffed with slightly cracked surface, 13 minutes. Let cool on baking sheets on rack for 2 minutes. Transfer cookies to racks; let cool completely.
In bowl, stir sugar, rind and juice until smooth. Thin with water for glazing consistency. Spread on cookies. Let dry, 20 minutes. Store airtight for up to 2 weeks. Makes about 2-1/2 dozen cookies.