These are fun to make, and to eat. They're three thumbprint cookies stuck together and filled with different jams -- strawberry, raspberry, and apricot. I also like how easy they are, and how decorative they look for the holidays.
Trios from Gourmet (December 2007)
2½ cups all-purpose flour
1 tsp salt
2 sticks (½ lb) unsalted butter, softened
1 cup sugar
1 large egg
1 tsp pure vanilla extract
About 2 tbs each of seedless raspberry jam, apricot preserves, and strawberry preserves
Whisk together flour and salt. Beat butter and sugar with an electric mixer until very pale and fluffy, about 4 minutes, then beat in egg and vanilla. At low speed, mix in flour mixture in 3 batches just until a dough forms. Divide dough in half and form each piece into a 6-inch disk, then chill, wrapped in plastic wrap, until firm, about 1 hour.
Preheat oven to 350° with rack in middle. Line 2 large baking sheets with parchment paper.
Roll 3 separate level teaspoons of dough each into a ball, then flatten each ball slightly (to 1 inch wide and less than ½ inch thick). Arrange them in a triangle with edges touching in center.
Then make a deep indentation in the center of each round with a wooden spoon handle. Make more cookies, arranging them 1 inch apart on baking sheets.
Fill indentations in each cookie with about 1/8 tsp jam (each cookie should have 3 different fillings).
Bake until cookies are baked through and golden brown on edges, 15 to 20 minutes. Cool on baking sheets 5 minutes, then transfer to racks to cool completely. Bake more batches on cooled baking sheets lined with fresh parchment.
Dough can be chilled up to 2 days. Cookies keep, layered between sheets of parchment, in an airtight container at room temperature 1 week.