Acorn Linzer Sandwich Cookies
In a medium bowl, whisk together flour and baking powder. Pulse pecans with confectioners' sugar, salt, and cinnamon in a food processor until finely ground. Transfer pecan mixture to the bowl of a stand mixer fitted with paddle attachment.Advertisement
Add butter and granulated sugar to bowl with pecan mixture and beat on medium speed until fluffy, 3 minutes. Beat in vanilla and egg. Reduce speed to low; add flour mixture and beat until combined. Divide dough in half. Working with one portion at a time, place dough between two pieces of lightly-floured parchment paper and roll out to 1/8 inch thickness. Refrigerate until firm, 30 minutes.
Preheat oven to 375°F. Cut out rounds with a 2 1/2-inch fluted cutter. Cut out centers of half of rounds with a 1-inch acorn cutter; reroll scraps and cut out more cookies. Arrange cookies 1 inch apart on parchment-lined baking sheets. Bake, rotating sheets once, until pale golden, 10 to 12 minutes. Transfer to wire racks; let cool completely. (Baked cookies can be stored in an airtight container at room temperature up to 3 days.)
Dust acorn-cutout cookies with confectioners' sugar. Spread 1 teaspoon jam on bottom of remaining cookies, then sandwich together. (Filled cookies are best eaten the same day.)