Sift together the all-purpose flour, kosher salt, and baking powder in a medium bowl, then set aside. This removes lumps and aerates the flour for a more tender cookie. While you're doing this, remove your butter and eggs from the refrigerator if they aren't already at room temperature—cold ingredients won't cream properly and will result in dense cookies.

In a large mixing bowl, beat the softened unsalted butter and packed brown sugar together for 4 minutes on medium-high speed. You're looking for a light, fluffy mixture that's noticeably paler in color—this process incorporates air into the dough, which helps the cookies rise and become tender. Stop halfway through and scrape down the bowl to ensure everything is evenly combined.

Add the creamy peanut butter and softened cream cheese to the creamed butter and sugar, then beat for 2 minutes until fully combined. The cream cheese adds richness and a subtle tang that balances the peanut butter beautifully. Next, add the room-temperature eggs and vanilla extract, beating for 1 minute until the mixture is smooth and homogeneous. I like to use pure vanilla extract rather than imitation—the flavor difference is worth it in a cookie this simple.

Add the dry ingredient mixture from Step 1 to the wet mixture in three additions, mixing on low speed after each addition until just combined. Don't overmix once you add the flour—this develops gluten and makes cookies tough. Stop as soon as you don't see any white streaks of flour remaining. The dough will be thick and slightly stiff, which is exactly what you want.

Divide the dough into two equal portions and shape each into a disk about 1 inch thick. Wrap each disk tightly in plastic wrap and refrigerate for at least 1 hour. Chilled dough is much easier to roll and cut without spreading, and it helps the cookies maintain their shape during baking. While the dough chills, preheat your oven to 350°F and line your baking sheets with parchment paper.

Working with one disk at a time, roll the chilled dough to ¼ inch thickness on a lightly floured surface. Cut out cookie shapes using your desired cutter—linzer cookies are traditionally round. From half of your cut cookies, use a smaller cutter (about 1 inch) to cut out a window in the center of each cookie, then place all cookies on parchment-lined baking sheets. Bake for 12-14 minutes until the edges are lightly golden but the centers still feel slightly soft—they'll continue to cook as they cool. I find the cookies are perfect when the edges are just barely turning brown, as overbaking will make them too crispy.

Cool all baked cookies on wire racks until they reach room temperature. Once cooled, spread about 1 tablespoon of seedless raspberry jam on each whole cookie (the ones without windows). Top each jam-filled cookie with a windowed cookie, pressing gently so the jam shows through the center cutout. If desired, lightly dust the finished cookies with powdered sugar for a classic bakery appearance. These cookies are best served the same day but will keep in an airtight container for up to 3 days.