Combine butter and sugars in a large bowl and use an electric mixer to beat until creamy.

Add egg yolk and stir well.

Add salt, vanilla extract, and almond extract (if using). Beat until well-combined.

With mixer on low-speed, gradually add flour until completely combined. Dough may be crumbly.

Add nonpareils (if using) and fold into dough.

Divide dough into 2 parts and work into a 2" wide log shape. Transfer to refrigerator to chill.

Preheat oven to 350ºF (175ºC) and line a cookie sheet with parchment paper.

Remove one cookie dough log from the refrigerator and use a sharp knife to cut into ¼" slices.

Place slices on prepared cookie sheet about 1" apart and bake for 10-12 minutes until edges are golden brown.

Allow to cool on baking sheet before serving. Optional: dip cooled cookies in chocolate and top with sprinkles.