Using a fork, dip a circle of cake into warm rose-colored frosting, coating top and sides. Let excess frosting drip back into bowl. Using another fork, slide frosted cake onto paper. Decorate 10 more with rose-colored frosting. Scatter tops of 4 with sprinkles. Using frosting in plastic bag, pipe out the word "sweetie" onto 7 of the decorated circles. Decorate 10 more cakes with pale-pink frosting. (Reheat frostings if necessary.) Place cakes with the word "sweetie" among the other decorated cakes on a serving platter.