Using a food processor or a knife, chop the nuts into small pieces. Clean out the food processor for later if you used it.
In the bowl of a stand mixer or a mixing bowl, beat the butter and powdered sugar until light and fluffy, about 3-4 minutes.
Add the vanilla to the butter mixture and mix until combined.
Add the nuts to the butter mixture and mix to combine.
Add the flour and salt to the butter mixture and mix until fully combined.
Use a cookie scoop or a tablespoon, portion the cookies out and roll them between your hands to form balls. Place the balls on the prepared cookie baking tray.
Bake
Bake the cookies for about 13-15 minutes.
You don't want these to brown or they will dry out too much. If the edges start to brown at all, take them out. Internal temperature should be 175°F (80°C).
Sugar Coating
Place the powdered sugar and freeze-dried strawberries into the bowl of a food processor. Process until very fine.
When the cookies are done baking, let them cool for about 5-10 minutes. While still a little warm, roll them in the powdered sugar mixture to coat.
After they have cooled, you can optionally roll them again in the sugar mixture. This will give them a thicker and more colorful coating.
Notes
If your cookies are spreading too much, chill the dough balls for about 15 minutes before baking.