The Wardrobe

In Ronald's old house, there is an urn of Grandma's on the mantle but it's actually filled with gum. Pick up two pieces of gum from the urn to save you some time. A bit later during the moving segment, you will be in a room with a giant Moai head. Give a piece of gum to the Moai head, then talk to him to get it back (give him the second piece of gum to continue with the story). Still a bit later, at the construction site, put the gum in the cement mixer and you will get gum that is quickly solidifying. To save time, I would make a save at this point. Wait for 15-20 minutes of real time and this trophy will unlock. Reload your save after it does.

Note: This must be done before using the solidifying (not solidified) gum in the microwave.