1. 1. Mix Royal Icing So first, mix the three ingredients in a bowl using a whisk. You can also use a stand mixer if you own one. After they blend, lift the whisk and watch as the icing drips. If it drips within ten seconds, you just made perfect icing for your house. But if it takes more than that, add water in tiny amounts and whisk till you get the right consistency.
2. 2. Cut the Pop TartsUse your serrated knife to saw through the pop-tarts instead of pressing down on them. This way, they'll be less likely to break.
3. You'll need to cut the front, back, roof, front door, and sides. Here are the detailed instructions, and make sure not to throw any scraps till you finish the recipe.

Front and Back Walls

1. You'll need to cut two pop-tarts for the front and back walls. Grab one, and lay it on the cutting board. Then, cut a diagonal line from the middle of the upper line of the pop-tart toward the right edge. Repeat the same step with the left edge. Now, your pop-tart should look like a triangle from the top. Follow the same steps with the second pop-tart. In one pop tart, cut out an opening for a door carefully with your knife.
2. 
   Side Walls
3. Cutting pop-tarts for the side walls is insanely easy. All you have to do is lay two pop-tarts in front of you and cut a small section off of their tops. They should be the same height as the front and back walls with no triangles on top.
4. 
   Roof
5. As for the roof, you'll need two whole pop-tarts, so there's no handy work here!
6. 3. Assemble the HouseYou'll need the front, back, and side walls to assemble the merry holiday house. First, prepare your piping bag by pushing your piping tip through its small opening and making sure it fits. Next, fill the bag with icing and close it from above by twisting it a couple of times or using a plastic tie.
7. 
   You can use a Ziploc bag or a plastic sandwich bag if you don't have a piping bag.
8. Use the icing to cover the sides of your trimmed pop-tarts. Then, stick them together so that the side walls face each other and the front and back walls face each other. Next, add icing on the top lines of your house to prepare for the roof.
   
9. 4. Add the RoofStick one pop-tart on top of the left side of the house. Then, cover its edges with royal icing and adhere the second pop-tart to it
10. 5. Decorate the Gingerbread HouseIdeally, you should wait for two or three hours before decorating. This way, you ensure that the icing is completely dry.
11. To decorate your house, start piping more icing on the roof and around the edges. Then, sprinkle some sparkling or powdered sugar to mimic snow. Decorate to your hearts content!