2 ½ cups all purpose flour
¼ tsp cream of tartar
⅛ tsp table salt
1 cup unsalted butter, softened to room temperature, or if using salted butter leave out ⅛ tsp salt
½ cup granulated sugar
2 tbsp confectioners' or icing sugar
1 large egg, at room temperature
½ tsp pure vanilla extract
¼ tsp pure almond extract
6 tbsp good quality raspberry jam, like Crofters Just Fruit Spread
In a medium bowl whisk the flour with the cream of tartar and salt (if using) until well blended.
With a stand mixer (use the paddle attachment) or a hand mixer, beat the butter, sugar and confectioners'/icing sugar in a large bowl on medium speed until light and fluffy, about 4 minutes, scraping the bowl as needed.
Add the egg, vanilla extract and almond extract and beat until blended. Add the flour mixture and mix on low speed until just blended. Do not overbeat.
On a lightly floured surface divide the dough into six equal pieces. If the dough is very soft wrap each portion and refrigerate until firmer, about 1 hour.
Heat oven to 350ºF and have ready two large, ungreased baking sheets (or line them with nonstick baking liners). If the dough is in the refrigerator remove and unwrap. Using your hands or a rolling pin (or both), shape each piece of dough into a flat 12" x 1 ½" strip about ¼" thick, dusting with flour as needed.
Transfer dough strips to the prepared baking sheets, spacing them about 3" apart. Using the butt end of a butter knife handle dipped lightly in flour, make an indentation down the middle of each dough strip (this will widen the strip to about 1 ¾" and make a depression about halfway down into the dough strip.)
Spread 1 tbsp raspberry jam evenly down the indentation of each dough strip. Bake until the cookie strips are lightly browned on the bottom and edges, about 20 minutes.
Allow the cookie strips to cool on the sheets for 5 minutes before carefully transferring to racks to cool completely. When cool cut each cookie bar with a serrated knife on the diagonal into 1" thick diamond shapes.