In a medium pot, heat the margarine, corn syrup, and brown sugar over medium-low heat, stirring constantly until the margarine is melted.

Pour the hot mixture into your bowl with the dry ingredients and mix with a spatula until a dough forms and all ingredients are well combined.

Cut the dough into two equal discs and wrap each in plastic wrap. Chill in the refrigerator for about 20 minutes.

Preheat the oven to 350F and prepare your work surface and rolling pin with flour.

Pinch off 1/4 of the dough at a time and keep the rest wrapped in plastic so it doesn’t dry out. Lightly flour the piece of dough you are working with over a piece of parchment paper and roll it out to 1/8″ thick for harder and more precisely shaped cookies or 1/4″ for softer, chewier, and slightly puffed shapes.

Transfer the cookie cutouts over parchment paper to an aluminum baking sheet and bake at 350F for 7-20 minutes. For tiny detail pieces that are thin, bake for the lower 7 minutes. For cookies, bake for 10 minutes. For large, thicker shapes like walls and roof pieces, 20 minutes will bake a sturdy design. If it’s your first time, you can take the cookies out, let them cool, test the hardness, and even rebake for longer to harden further. You can check for doughy centers by watching for a consistent color over the entire cookie.

Let cool on the cookie sheet for a few minutes before transferring your cutouts to a cooling rack. When they are completely cool, you can start decorating them!

In the bowl of an electric stand mixer, add the ingredients and whisk on high for 8-10 minutes or until soft peaks form. Adjust for color with more cocoa powder at teaspoon at a time.

Add to a piping bag with a very small piping tip (I prefer #2), and you’re ready to go! You can leave it out on the countertop for multiple days of use.