Happy Halloween Thumbprint Cookies

Directions

1. In a large bowl, combine the granulated sugar, butter, shortening, salt, and vanilla extract. Use a mixer to blend these ingredients until the mixture becomes smooth and creamy, which should take approximately five minutes.
2. Crack the egg into the bowl and blend it in thoroughly. Pause occasionally to scrape down the sides of the bowl to ensure everything is evenly incorporated.
3. Gradually pour in the flour while mixing on low speed. Stop mixing as soon as the flour is just combined; you might need to finish incorporating the last bits by hand. If the mixture feels too crumbly or dry, add water one teaspoon at a time until the dough comes together.
4. Portion the dough into balls roughly the size of a baseball.
5. Roll each ball between your palms to create a long cylinder approximately one inch thick.
6. Wrap each dough log tightly in waxed paper or plastic wrap. Place them in the refrigerator to chill until firm.
7. Preheat your oven to 350 degrees Fahrenheit.
8. Take the chilled dough logs out of the fridge and slice them into rounds that are half an inch thick.
9. Arrange the slices cut-side up on a baking sheet lined with parchment paper or lightly greased. Since this dough does not spread during baking, use your fingers to gently smooth out any cracks or loose crumbs for a neater look. If the dough is too stiff to shape easily, let it sit at room temperature for a few minutes to soften slightly.
10. Press your thumb or the rounded handle of a whisk into the middle of each cookie to create a deep well.
11. Bake the cookies for eight to ten minutes, watching closely until the edges just start to turn a light golden color. Avoid letting them brown too much.
12. While the cookies are still warm, press your thumb or tool into the center again to refresh the indentation.
13. Allow the cookies to cool completely on the baking sheet.
14. Prepare the frosting by mixing the confectioner's sugar, vanilla, and salt in a bowl. Add water one tablespoon at a time, stirring until you reach a consistency that allows you to slowly drizzle it from a spoon to form a small puddle in the cookie wells.
15. Split the frosting into separate small bowls. Stir in your chosen food coloring to create different hues.
16. Using a small spoon, carefully drizzle the colored frosting into the center of each cooled cookie.