Cream the butter and sugar together using mixer, then add salt, almond extract, baking powder and 1 egg. Mix to combine.
Once fully incorporated, sift in flour 1 cup at a time, mixing to combine between each cup. After adding the 3rd cup, mix only until combined, do not over mix. Take the dough out and knead it to form ball. Be mindful not to overwork it.
If the dough doesn't come together fully in the bowl, don't worry. As long as it forms a solid ball with kneading, you're good to go.
Roll between pieces of parchment paper to about 1/4 inch thickness. Place the sheet of dough with the bottom piece of parchment paper on a cookie sheet (you will bake the cookies on the parchment paper to prevent sticking). Cut shapes into the dough, making sure to leave a little space in between each one.
Remove excess dough and bake for 5 minutes. Then rotate the pan and bake for another 5 minutes. Depending on your oven, you may need to bake for 6 minutes on each side. After 10 minutes in the oven, check to see what they look like. If they still look wet, they're not done. If they're brown around the edges they're overdone.
Remove from oven and let cool, then place on pieces of paper towel to absorb excess moisture. Let set for at least an hour or two before decorating.
Prepare the icing.
In a bowl combine merengue powder, warm water, imitation butter flavor and imitation vanilla. Whisk to dissolve the merengue powder.
In a larger bowl, preferable a stand mixer, add powdered sugar. Add in the merengue liquid mixture and mix on high until the icing becomes bright white and forms stiff peaks. Be patient, this takes time! Next add light corn syrup and mix to combine. Cover with a wet towel.
Mix your colors in separate bowls. Add water a little bit at a time to get the consistency right - you want it to be runny but also firm. As a rule of thumb, drizzle a line of frosting over the bowl of frosting and start counting. The pattern should sink completely into the frosting in 20 seconds. If it sinks faster than that, you'll have trouble with the icing running off the sides of the cookies. If it takes longer than that, your icing will be too thick to flood the cookie. Once you have the right colors and consistency, you're ready to fill your icing bags and start decorating.
Always make sure you overfill your cookies (put way more icing than you'd expect) to give it a nice plump look, and always run a toothpick through the icing to prevent pitting and to finesse the shape.
Set decorated cookies in front of a fan to dry and always make sure cookies are completely dry in between frosting layers. Frost with multiple colors, decorate with edible markers if desired and/or even try edible glitter. Enjoy!