Beat the butter for several minutes, until creamy. Slowly add the sugar. Add syrup, egg yolk, and extracts. Stir in the flour and nuts.
Divide dough in half. On plastic wrap, shape the dough into long log shapes about 1 1/2 inches or so high. Completely wrap the logs and stash in fridge until firm, at least two hours. They can also be frozen.
Preheat oven to 350-degrees.
Slice logs into 1/2 inch thick rounds and set on parchment papered or greased baking sheet. Bake for 18-20 minutes, until cookies are set and just barely tinted with color.
OM NOM NOM.