• Place 6 pop tarts on the cutting board.
  

Roof

• You will be making cuts on 4 out of 6 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. Repeat this step so that you have 2 house-shaped pop tarts.
  

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 (un-cut), 2 house-shaped pieces, and 2 wall pieces.
  
• Combine powdered sugar and water to make a royal icing glue. Add water ½ teaspoon at a time until desired consistency is achieved (2 ½ teaspoons works well for me). Spoon icing into a Ziploc bag and cut the tip off. Glue the 4 walls together with icing and hold in place for a minute or so.
  
• Add the roof pieces and hold in place for a minute or so.
  
• Let houses stand AT LEAST 30 minutes before decorating. If making these with kids, assemble the houses the day before you want to decorate them to allow the pop tarts to harden a bit.
  
• Dip decorations into icing or pipe icing onto houses to decorate.