In a bowl, mix the flour, cornstarch, and salt. Set aside.
In a large bowl, cream the butter, sugar, and brown sugar until combined. Add the egg yolk and almond extract and beat well.
Gradually incorporate the dry ingredients into the wet ingredients and mix well until combined.
Scoop out 1-tbsp of dough at a time and roll into balls. Place on a lined cookie sheet.
Using your thumb or the back of a spoon, press into each ball of dough to form a small indent. Place in the freezer to chill for 1 hour.
When ready to bake, preheat the oven to 375°F.
Carefully spoon out apricot preserves into each cookie. Bake for 12-14 minutes or until lightly browned.
Let cool and top with sprinkles and powdered sugar. Enjoy!