Preheat your oven to 350°F (175°C) and line two baking sheets with parchment paper or a Silpat mat.

In a large bowl, cream butter and both sugars until light and fluffy—about 2 minutes with an electric mixer. You’ll see pale, pillowy peaks form.

Add the peanut butter, egg, and vanilla extract. Beat on medium speed until combined. Scrape down the sides; you don’t want any pockets of sugar hiding.

Whisk together flour, baking soda, and salt in a separate bowl. Slowly add to the wet mix, stirring until just combined—don’t overmix or the cookies get tough.

Scoop dough into 1½-tablespoon mounds. Press each mound into a flat disk in your palm. Drop about 1 teaspoon of jam into the center. Fold edges up and around the jam, rolling gently into a ball so the filling is sealed.

Bake for 10–12 minutes, until edges are set and tops have tiny cracks. The centers will still look soft—that’s perfect.

Let cool on the sheet for 5 minutes, then transfer to a wire rack to finish cooling. The jam sets as they cool, giving you a gooey core inside.