Preheat your oven to 375°F and line two 13x9 inch baking sheets with parchment paper.

In a medium bowl, whisk together the all-purpose flour, cornstarch, and salt. Set aside.

In a large bowl, cream the room-temperature butter with the light brown sugar and granulated sugar until light and creamy, about 2-3 minutes.

Add the egg yolk, vanilla extract, and almond extract to the butter-sugar mixture and mix on low speed until combined.

Gradually add the dry ingredients to the wet ingredients, mixing at low speed to create the dough.

Using a tablespoon-sized dough scoop, form dough balls and place them 2 inches apart on the prepared baking sheets, pressing a heart shape into each ball.

Chill the shaped cookie dough in the freezer for about 30 minutes or refrigerate for 1 hour.

Remove the cookie sheets from the freezer and add about 1/2 teaspoon of heated raspberry jam into the heart indentations.

Bake the cookies for 10-12 minutes until the edges are lightly golden brown.

Let the cookies sit on the baking sheets for 5 minutes before transferring them to a cooling rack.