Prepare pans and preheat oven. Preheat oven to 350 degrees F. Line 2 baking sheets with parchment paper.
Cream butter and sugar. Beat butter and granulated sugar on medium high until light and fluffy, about 2 minutes.
Add egg yolk and vanilla. Add the egg yolk, mixing until combined. Add extract and mix just until combined. Scrape down the sides of the bowl as needed.
Add the dry ingredients. Add the flour and salt and mix just until combined.
Shape cookies. Using a tablespoon scoop the cookies into 1 inch balls. Roll each cookie into a ball using your hands and place on the prepared cookie sheets about 2 inches apart. With your thumb or the back of a ¼ teaspoon, dent each cookie in the center, and put ¼ teaspoon jam into each indent.
Bake and cool the cookies. Bake for 15-17 minutes until light golden brown on the bottoms. Allow to cool on the cookie sheets for 5 minutes, before moving to a cooling rack to completely cool.
For the glaze. Mix all ingredients for glaze in a small bowl. If it's too thick, add a bit more milk. If it's too thin, add a bit more powdered sugar. Drizzle over cookies once they are cooled.