Preheat oven to 350 degrees. Line 2 baking sheets with parchment paper or silicone baking mats and set aside.
In a large bowl, stir butter, sugar, salt, vanilla, and flour until crumbly dough forms. {Right near the end of stirring, I use the warmth of my hands to help it come together.
Using a small cookie scoop {2 teaspoon size} divide the dough into even mounds of dough.
Roll dough to create a smooth cookie ball and press an indentation into the center using your thumb.
Bake 8-10 minutes or until puffed and barely golden brown on the bottom.
Cool 10 minutes.
Scoop 1 teaspoon of jam into the center of each cookie and drizzle with glaze, if desired.