You will be making cuts on 3 out of 5 of the pop tarts. The 2 that aren't cut are the roof pieces. You can set those 2 pop tarts to the side if you'd like.
Front and Back Walls
Take 1 pop tart and place it on its side, right next to another pop tart.
Cut on a diagonal from the corner of the pop tart that it on its side, to the center of the middle pop tart. Repeat on the other side.
You should now have a pop tart that looks like a house.
Side Walls
Remember that pop tart that you turned on its side? Go ahead and stand it up again. Place it next to one of the house-shaped pop tarts, lining up the corners, and cut horizontally across. Repeat.
You should now have two roof pieces (uncut), 1 house-shaped piece, and 2 wall pieces.
Combine powdered sugar and water to make a royal icing glue. Add water ½ teaspoon at a time until the desired consistency is achieved (2 ½ teaspoons works well for me). Spoon the icing into a Ziploc bag and cut off the tip. Glue the 3 walls together with icing and hold in place for a couple minutes then allow it to stand on its own for 10 minutes.
Add the roof pieces and hold in place for a couple of minutes.
Other than the angel, I did not decorate the stable; I simply added the characters around it. If you want to add candy and decorations to the walls and roof, make sure to let the stable stand AT LEAST 30 minutes before doing so to allow the icing to dry completely.
Mary:Use icing to stack and secure two Rolo candies for the body. Unwrap a vanilla tootsie roll and warm it in your hands. Roll into a ball. Use icing to secure it to the top of the Rolo stack for a head. Unwrap a chocolate tootsie roll and warm it in the microwave for 5-7 seconds. Flatten into a rectangle, then place over the head to create hair.
Joseph:Use icing to stack and secure two Rolo candies for the body. Unwrap a vanilla tootsie roll and warm it in your hands. Roll into a ball. Use icing to secure it to the top of the Rolo stack for a head. Unwrap a chocolate tootsie roll and warm it in the microwave for 5-7 seconds. Flatten into a rectangle. Cut a thin strip off the bottom and set it aside. Place the rectangle over the head to create the headpiece. Add the strip across the front for the headband.
Baby Jesus: Unwrap a vanilla tootsie roll and warm it in your hands. Roll into a ball. I only used ⅔ of the tootsie roll because I wanted a smaller head than Mary and Joseph. Unwrap a chocolate tootsie roll and warm it in your hands. Shape the chocolate tootsie roll into a body (resembling a baby's body wrapped in a blanket). Press the body against the head to attach. You can use icing, but I didn't find it necessary.Place on top of a square pretzel (manger).
Shepherds:Follow the instructions for Joseph, but add a pretzel stick for a staff, using icing to attach it.
Angel:Follow the directions for Mary, but use a vanilla tootsie roll for the hair as well. Attach the pretzel wings to the back using icing. Allow the icing to set before attaching the angel to the nativity.
Animals:Attach the animals to the side of the nativity using icing.
Finishing touches:Sprinkle toasted coconut around the platter/plate to look like straw. Add any other details that you'd like.
Video
Notes
Icing should be the consistency of craft glue.
When cutting pop tarts, use a serrated knife and gently saw. Don't press the knife down hard.
Toasted coconut: Heat oven to 375 degrees. Toast coconut 10-12 minutes, checking every so often and stirring to prevent burning.