This is our simple version using the microwave chocolate cake in a mug idea.

This one looks fab and modern and has a very easy push/pull mechanism to make the cake rise in the mug.

For this one print:-

The card size of your choice onto heavyweight card, 280-300gsm (this one's 7" x 5")
The cake pull-ups sheet onto the similar heavyweight card

To make the card:-

1/ Cut out the card blank with a craft knife and ruler, then crease with an embossing tool but do not fold at this point.

2/ Using a nice sharp craft knife and ruler, cut slots where indicated at the base of the mug and also the full width of the top of the mug.

3/ Cut out the cake pull-up using a craft knife and ruler for the straight parts, freehand for the rounded part (tip:- hold the knife firmly and move the card, not the knife to get the best results).

4/ Slide in the cake pull-up from the inside of the card.

5/ Make sure the cake pulls up and down easily.