Creating Danish Butter Cookies is a straightforward process. Follow these steps to achieve the best results:

1. Preheat Oven: Preheat your oven to 350°F (175°C) and line two baking sheets with parchment paper.
2. Cream Butter and Sugar: In a large mixing bowl, cream together the softened butter and granulated sugar until light and fluffy.
3. Add Vanilla: Mix in the vanilla extract until well combined.
4. Combine Dry Ingredients: In a separate bowl, whisk together the all-purpose flour and salt.
5. Mix Dry and Wet Ingredients: Gradually add the dry ingredients to the butter mixture, mixing just until combined. Do not overmix.
6. Shape Cookies: Using a piping bag or cookie scoop, pipe or scoop dough onto the prepared baking sheets, leaving space between each cookie.
7. Add Egg Wash: In a small bowl, beat the egg yolk and brush it lightly over the tops of the cookies for a golden finish.
8. Add Toppings: If desired, sprinkle colored sugar or add chopped nuts on top of the cookies.
9. Bake: Place the baking sheets in the preheated oven and bake for 12-15 minutes, or until the edges are lightly golden.
10. Cool: Remove the cookies from the oven and let them cool on the baking sheets for a few minutes before transferring them to wire racks to cool completely.

Following these steps ensures that your Danish Butter Cookies turn out perfectly every time.