How to Make It
Position racks in middle and lower third of oven; preheat to 375°. Whisk together first 3 ingredients in a large bowl. Beat butter and next 3 ingredients at medium speed with a heavy-duty electric stand mixer 3 to 5 minutes or until light and fluffy. Add egg and vanilla; beat 1 to 2 minutes or until egg is incorporated. Add flour mixture in 3 batches; beat at low speed until just combined. Using a 1-inch cookie scoop, drop dough by level scoopfuls 2 inches apart onto 2 parchment paper-lined baking sheets. (Use heaping tablespoonfuls, if you don't have a 1-inch scoop.) Flatten tops of each dough portion slightly, using a fork to create a crisscross pattern on each cookie. Bake cookies at 375° for 5 minutes, placing 1 baking sheet on middle oven rack and 1 sheet on lower oven rack. Rotate pans. Bake 5 to 6 more minutes or until cookies are golden brown. Cool 5 minutes on pans. Transfer cookies to wire racks; cool completely (about 20 minutes). Spoon about 1 Tbsp. jam onto bottom side of 1 cooled cookie; top with another cookie to make a sandwich. Repeat with remaining jam and cookies.
Back in the Day Bakery: Made with Love