1/2 cup (1 stick) unsalted butter, room temperature
2 tablespoons lard, room temperature
1/2 cup sugar
2 large egg yolks
Zest and juice of 1 lemon
2 cups all-purpose flour, plus more for dusting
6 tablespoons raspberry jam
Put butter, lard, and sugar in the bowl of an electric mixer fitted with the paddle attachment. Mix on medium speed until pale and fluffy. Mix in egg yolks, lemon zest, and lemon juice. Reduce speed to low. Gradually mix in flour. Flatten dough into a disk; wrap in plastic wrap. Refrigerate until firm, at least 1 hour or overnight.
Preheat oven to 325 degrees with racks in upper and lower thirds. Let disk of dough stand at room temperature just until soft enough to roll, about 10 minutes. Roll out dough on a lightly floured surface to 1/4 inch thick. Cut out cookies with a 3-inch crescent-shaped cookie cutter. Transfer cut cookies to parchment-lined baking sheets and chill until firm, about 20 minutes. Reroll scraps; cut shapes.
Bake, switching positions of sheets and rotating halfway through, until edges turn golden, 12 to 15 minutes. Cool completely on wire racks.
Spread flat side of half the cookies with 1 teaspoon raspberry jam each; sandwich with remaining cookies.