Line two 13x9 baking sheets with well-fitting parchment paper.

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

In the large bowl of a stand mixer or with a hand mixer, cream together the butter with the sugars using the paddle attachment for 2-3 minutes until lighter and creamy.

Scrape down the bowl and mix in the egg yolk, vanilla, and almond extract.

Set the mixer to low and slowly add the dry ingredients into the wet mixture, scraping down the bowl as needed.

Using a 1 tablespoon-sized dough scoop, make dough balls and roll them as smoothly as possible between your palms.

Place each dough ball 2 inches apart onto the prepared baking sheet. Press a heart shape gently into the top of each cookie dough with your pinky finger.

Place the cookie sheet into the freezer for 30 minutes or the refrigerator for 1 hour.

Preheat the oven to 375°F while the cookies chill.

Put the raspberry jam into a small microwave-safe bowl and heat for 10-15 seconds until it’s slightly runny.

Using a 1/4 teaspoon or a very small spoon, fill the heart indent with about 1/2 teaspoon of jam.

Bake the cookies for 10-12 minutes until the edges start to turn golden brown.

Let the cookies cool on the baking sheet for 5 minutes, then transfer them to a cooling rack.