In a large mixing bowl, beat the softened butter and granulated sugar together for 2-3 minutes until light and fluffy. This creaming process incorporates air into the butter, which helps create the tender, crumbly texture that makes shortbread special. Add the almond extract and beat for another 30 seconds to distribute it evenly throughout the mixture.

In a separate bowl, whisk together the flour and salt to distribute the salt evenly and break up any lumps. Add the dry mixture to the creamed butter mixture and mix on low speed until just combined—the dough should come together without any visible flour streaks. I prefer to finish this by hand with a wooden spoon to avoid overworking the dough, which can make the cookies tough rather than tender and crumbly.

Working with about a tablespoon of dough at a time, roll it into a 1-inch ball between your palms. Place each ball on an ungreased baking sheet, spacing them about 1.5 inches apart. Using your thumb or the back of a small spoon, gently press a shallow indent into the center of each ball—don't press too hard, or you'll crack the dough. Spoon about 1/2 teaspoon of raspberry jam into each indent, filling it generously but not overflowing.

Cover the baking sheet with plastic wrap and refrigerate for at least 2 hours, or freeze for at least 1 hour. Chilling is essential—it prevents the cookies from spreading too much during baking and helps them maintain their defined shape and indents. If you're short on time, the freezer option works beautifully and actually yields slightly better results in my experience.

Preheat your oven to 350°F. Bake the chilled cookies for 13-16 minutes, until the edges are just barely golden but the centers still look pale and slightly underbaked—they should look slightly undercooked when you remove them from the oven. This is key to maintaining that tender shortbread texture; the cookies will continue to firm up as they cool.

While the cookies bake, whisk together the sifted icing sugar, milk, and almond extract in a small bowl until smooth and pourable. Set aside. Once the cookies come out of the oven, let them cool on the baking sheet for 5 minutes to set slightly, then transfer them to a wire cooling rack to cool completely. This initial resting period on the sheet prevents them from breaking as you move them.

Once the cookies are completely cooled, drizzle the icing glaze lightly over the top of each cookie, allowing it to pool slightly around the jam-filled center. This adds a delicate sweetness and elegant presentation without overwhelming the subtle almond flavor of the shortbread itself.