Preheat your oven to 350°F (175°C) and line a baking sheet with parchment paper.
In a mixing bowl, cream the softened butter and granulated sugar together using an electric mixer or whisk until light and fluffy, about 2-3 minutes.
Add in the almond extract and mix until just combined.
Gradually add the all-purpose flour and salt to the butter mixture, mixing until a soft dough forms.
Use a cookie scoop or tablespoon to portion out the dough and roll it into small balls (about 1 inch in diameter). Place them on the prepared baking sheet, spacing them about 2 inches apart.
Using your thumb or a toothpick, make an indentation in the center of each cookie.
Fill each indentation with approximately 1 teaspoon of raspberry jam.
If desired, sprinkle the tops of the cookies with sliced almonds.
Bake in the preheated oven for 12-15 minutes, or until the edges of the cookies are lightly golden.
Remove from the oven and allow to cool on the baking sheet for a few minutes before transferring to a wire rack to cool completely.
Optional: Dust with confectioners' sugar before serving.