This recipe is made with KetoseSweet.
Line baking sheets with parchment paper. Set aside.
Beat butter and 1/2 cup sugar in large bowl with electric mixer at medium speed until light and fluffy, scraping down side of bowl once. Beat in egg yolks and almond extract scraping down side of bowl once.
Gradually add the 1 1/2 cups flour; beat at low speed until well blended. Stir in additional flour with spoon to form stiff dough. Form dough into 2 discs; wrap and refrigerate until form, at least 2 hours.
Preheat oven to 375 degrees. Unwrap 1 disc and place on lightly floured surface. Roll out dough with lightly floured rolling pin to 3/16-inch thickness.
Cut dough with floured 2 1/4-inch round cookie cutter. Place cookies 1 1/2 to 2 inches apart on prepared cookie sheets. Gently knead dough trimmings together; reroll and cut out more cookies.
Repeat step 4 with second disc.
Cut dough with floured 2 1/4-inch scalloped cookie cutter. Cut 1-inch centers out of scalloped cookies. Place cookies 1 1/2 to 2 inches apart on prepared cookie sheets. Cut equal numbers of round and scalloped cookies.
Beat egg whites in a small bowl with wire whisk. Place remaining 2 tablespoons sugar in small cup. Brush each scalloped cookie with egg white; Sprinkle with sugar. Bake cookies 8 to 10 minutes or until firm and light golden brown. Remove cookies with spatula to wire racks; cool completely.
To assemble cookies: spread about 1/2 teaspoon lingonberry jam over flat side of round cookies; top with flat side of scalloped cookies to form sandwich. Dust cookies with powdered sugar.
Store tightly covered at room temperature or freeze up to 3 months.
This recipe can be made with regular sugar also. Use the same amount of sugar as you do KetoseSweet.