It's money.

OK, it's also all about the colorful stripes and the confetti sprinkles and the look on the recipient's face when you tell them their gift is inside the cake! Here's how to make it.

First, procure a pull-dispenser money box with a roll of plastic sleeves — check the link below for the one we bought on Amazon. You can also find these boxes in some well-stocked baking specialty shops. Gather the cash (or fun coupons or sweet notes — whatever paper object you want to gift!) and insert it into the sleeves. Consider using smaller denominations to prolong the surprise — the more bills, the better!

Roll up the money leaving 3 to 4 inches of the top bill sticking up.

Place the roll of money inside the box, and thread the top bill through the opening in the lid. Close the lid and attach the clip to the end of the plastic sleeve — this is the part that will be pulled from the cake. Push the top bill down into the box so that the clip fits securely in its opening on the lid.

Fill, stack and crumb-coat two cake layers, leaving the top of the cake unfrosted. Refrigerate the cake until the frosting is set, about 30 minutes. Then place the money box in the center of the top of the cake and cut around the box with a paring knife.

Use a spoon to dig out the cake in the center of the cut-out. Remove cake a little at a time and insert the box to gauge how much more cake needs to be removed. When you're done, the top of the box should be even with the top of the cake. Cover the sides of the cake with a thick layer of frosting. Cover the top of the cake also, but avoid covering the money box in the center.

While the cake is freshly frosted, run a cake comb (with 1/4-inch teeth) around the outside of the icing, making even grooves around its entire circumference. Chill the cake until the frosting is firm.

Prepare more frosting by dividing it and tinting it a rainbow of colors. Transfer each color to a piping bag with a very small hole snipped in each bag’s tip.

Fill each groove with a different color frosting and use a bench scraper to smooth the edges of the cake.

The end result should produce a striped rainbow effect around the edges of the cake. Refrigerate the cake until well-set, about 30 minutes. You will have leftover frosting, so save it for the next step!

Lay two large pieces of plastic wrap overlapping on a work surface. Snip a larger hole in the end of each color of frosting in the piping bags (about 1 1/2 inches). Pipe lengths of each color frosting side-by-side in the center of the plastic wrap. Roll the frosting together inside the plastic and twist the ends. Snip one end and place it in a large piping bag fitted with a large French decorator tip.

On a piece of scrap parchment, pipe a short rope of frosting for practice (it's all about small circular motions of the wrist!). When all of the colors begin to show in a rainbow, you’re ready to decorate the top of the cake. Pipe a swirling rope of frosting on the top edge.

Cover the top center of the cake, including the top of the money box, with confetti sprinkles.

Insert a cake topper that says "PULL" into the top of the money box at the guide holes (the tension was enough to keep our topper in place).

This cake is fun to put together, but the best part is presenting it to the guest of honor! Faces will light up when they see the rainbow decoration, but even more so when you tell them to pull the topper...