Cream the softened butter and granulated sugar in a mixing bowl using a hand or stand mixer until the mixture is light and fluffy, about 2-3 minutes, and visibly increased in volume.
Add the egg and almond extract to the creamed mixture, and beat until fully combined, about 1 minute. The mixture should be smooth with a glossy appearance.
Gradually add the flour and salt to the wet ingredients, mixing on low speed until the dough begins to come together. Then, knead briefly by hand if needed until a cohesive dough forms.
Divide the dough into two equal portions, wrap each in plastic wrap, and chill in the refrigerator for at least 1 hour to firm up.
Preheat the oven to 350°F (175°C). Remove one dough portion from the refrigerator and roll it out on a lightly floured surface to about 1/8-inch thickness. Cut into rectangular shapes or use a cookie cutter as desired.
Use a small tool or the back of a piping tip to make tiny indentations in the center of each cookie rectangle. Fill these indentations with a small amount of jam, about ½ teaspoon each, creating a filled appearance.
Arrange the filled cookies on a parchment-lined baking sheet. Bake in the preheated oven for 8-10 minutes, or until the edges are lightly golden and crisp.
Remove the cookies from the oven and allow them to cool on the baking sheet for 5 minutes before transferring to a wire rack to cool completely. The cookies should be crisp, thin, and slightly delicate.
