Step 1
In a large bowl, with the mixer at medium speed, mix the butter and sugar until light and fluffy, about 3-4 minutes. Add vanilla and egg, mix until well combined. Scrape the sides of the bowl as needed.
Step 2
In a medium bowl, whisk together flour and salt. Add to butter-sugar mixture. Mix at slow speed until just combined. Wrap the dough in plastic wrap and chill for 30 minutes.
Step 3
Preheat oven to 350°F. Line three baking sheets with parchment paper.
Step 4
Remove the dough from the refrigerator and roll the dough about ¼-inch thick. Use a cookie cutter to cut out shapes. Place on prepared baking sheets and bake for 12-14 minutes until golden brown.
Step 5
Allow the cookies to rest on the baking sheet for 5 minutes and then transfer to a cooling rack. Allow the cookies to cool completely before icing.
Step 6
Prepare the icing. Combine all ingredients together in mixing bowl, except the food coloring.
Step 7
Beat on low speed until combined, then increase speed to medium high and beat for 5 – 8 minutes, adding 2-3 tablespoons more warm water, as needed. Icing should be stiff enough to hold a peak when tested.
Step 8
Add food coloring of your choice, adjusting the amount depending on the intensity of the color you desire. Use this thick icing to outline cookies.