I pulled numerous sources from my idea file for this 50th birthday pop up card.
On the front, the speech bubble says "We are not amused."
This is a one tier tabletop type pop up cake as demonstrated in this post: Building a Better Pop Up Cake Part 4.
Make the cake top
Cut out a 3" diameter circle of sturdy card stock for the cake top. Fold it in half. Measure out 3/4" on either side of the center fold and cut a slit on each side, parallel to the center fold. Each slit should be a tiny bit more than 1/2" long.
Attach crown to cake top
The crown is cut from a cupcake wrapper template designed by Monica Björk. I removed a great deal of the detailing on the pattern because I made it so much smaller (51% of original size).
The diameter of the base of the crown is 1.5". I added tabs on the right and left sides to attach it to the cake top. The tabs are 1/2" wide.
Glue the crown ends together.
Precrease the crown by folding it in half so the tabs are one on top of the other. Uncrease.
Slide the tabs of the crown through the slits on the cake top and tape them to the back side of the cake top.
Make the legs
Cut two long strips for the cake legs: 1/2" wide by 6" long. Divide each into 4 equal segments of 1.5" and crease.
Referring to the post mentioned above, glue legs to the cake top, and then glue the legs into the base card.
Wrap the sides
For the cake side, cut a strip of lightweight paper 1.5" wide by 11" long.
Scroll down in this post for detailed instructions for adhering the side piece.
Extreme Cards and Papercrafting: pop up cards, movable and mechanical cards, digital crafts and unusual papercrafts.