This is a Dorie Greenspan recipe for Linzer Sablés. These cookies are traditionally made for Christmas. I think they're quite perfect for Valentine's Day, withe red jam and a heart window. The dough is equal parts ground almonds and flour, as well as your normal cookie ingredients. Just like traditional roll outs, the dough is chilled before flattening and cutting out the shapes.
The most important thing is that you have two heart shaped cookie cutters in the same shape but differing sizes. One has to be small enough that it will fit inside the larger one while leaving you enough dough space that the cookie won't just fall apart. The other important thing to remember is that you need equal numbers of plain hearts and windowed hearts. Once that is done, they're ready to bake.
When the cookies have been baked and cooled, they are ready for assemble. I made two kinds of jam for these linzers, with fruit that was otherwise going to go bad. One is a strawberry balsamic jam, the balsamic cuts the sweetness of the strawberries nicely while still complementing the flavors. The second was a basic cranberry jam. (These are adult cookies, meant to surprise with the sweet and sour combination.)
After sandwiching the jam between the two cookies, a little sprinkling of powdered sugar, you have a beautiful treat for your Valentine. A platter of these cookies is really spectacular.