Cut a rectangle out of white fondant, about 1 inch wide by 6 inches long x 2 inches deep. Cut the long rectangle into smaller rectangles about 3/4 inch wide. Next, cut the small rectangles in half so that they're about 1 inch in height. Use your fingers to smooth and shape the small rectangles into book shapes as these will be the inside of the books.

Roll out a piece of the dark colored fondant to about ¼ inch thickness.

Cut the dark fondant into long rectangles that match the dimensions of the white book insides. Wrap each book inside with a piece of dark colored fondant, leaving one side open.

Cut off any excess fondant and press the dark colored fondant onto the white fondant to attach the cover to the book. Use a damp finger to adhere, if needed.

Repeat until all the book insides are covered.

Preheat the oven to 350 F. Line a muffin pan with cupcake liners.

In a large bowl, combine the sugar, flour, baking soda, baking powder, salt, and cocoa powder.

Add the egg, milk, oil, and vanilla extract and beat on medium speed until combined, about 2 minutes.

Stir in the boiling water (batter will be thin and runny).

Pour the batter into the prepared muffin pan and bake for 15 minutes or until a toothpick inserted into the center of the cupcake comes out clean.

Cool the cupcakes in the pan for 10 minutes before transferring to a wire rack to cool completely.

On medium speed, beat butter until light and fluffy, about 2 minutes.

Add in the marshmallow fluff and beat on low speed until just combined, about 30 seconds.

Gradually add in the sugar and vanilla and beat on medium speed until fluffy. Make sure not to overbeat the frosting as it will become tough.

Separate the frosting into two bowls. Stir a few drops of yellow food coloring into one of the bowls and a few drops of blue food coloring to the other bowl.

Transfer the yellow frosting to one piping bag and the blue frosting to a second piping bag. Cut the ends off the piping bags and place into a larger piping bag that has been fitted with a large star tip.

If the frosting feels warm or runny, place in the refrigerator to chill before frosting the cupcakes.

Using the large piping bag that has both the yellow and blue frosting, pipe the frosting onto the cupcakes in a swirl pattern.

Add a red fondant rose to the yellow side of the swirl and a fondant book to the blue side of the swirl.