Step 1: Prepare Your Dry Ingredients

In a medium-sized bowl, whisk together the all-purpose flour, baking soda, baking powder, and salt. Whisking not only combines these ingredients but also aerates them, which contributes to a lighter cookie texture. Set this bowl aside for later.

Step 2: Cream the Butter, Sugars, and Peanut Butter

In the bowl of a stand mixer fitted with a paddle attachment, or in a large bowl with a hand mixer, beat the softened unsalted butter, light brown sugar, and granulated sugar on medium-high speed until the mixture is light, fluffy, and pale in color. This process, known as creaming, should take about 3-4 minutes. Don’t rush this step! It’s essential for incorporating air into the dough, which results in a softer, chewier cookie. Once creamed, add the creamy peanut butter and beat for another 1-2 minutes until it is fully incorporated and the mixture is smooth.

Step 3: Incorporate the Wet Ingredients

Add the room temperature egg and pure vanilla extract to the peanut butter mixture. Beat on medium speed until just combined, scraping down the sides and bottom of the bowl as needed to ensure everything is evenly mixed. The egg acts as a binder, and the vanilla deepens the flavor profile.

Step 4: Combine Wet and Dry Ingredients

Reduce the mixer speed to low and slowly add the dry flour mixture to the wet ingredients. Mix only until the flour is just incorporated. Be very careful not to overmix at this stage. Overmixing develops the gluten in the flour, which can lead to tough, dense cookies instead of the soft and chewy texture we’re aiming for.

Step 5: Chill the Dough (The Non-Negotiable Step!)

Cover the bowl with plastic wrap and refrigerate the cookie dough for at least 1 hour, and up to 3 days. Chilling the dough is the most important secret to thick, flavorful cookies. It solidifies the fat (butter), which prevents the cookies from spreading too much in the oven. It also allows the flavors to meld and deepen, resulting in a more intense peanut butter taste.

Step 6: Preheat and Prepare for Baking

When you’re ready to bake, preheat your oven to 350°F (175°C). Line two large baking sheets with parchment paper or silicone baking mats. This prevents the cookies from sticking and makes for easy cleanup. Place the 2 tablespoons of granulated sugar for rolling in a small, shallow bowl.

Step 7: Shape the Cookies

Remove the chilled dough from the refrigerator. Using a medium cookie scoop (about 1.5 tablespoons), portion out the dough into uniform balls. Roll each ball between your palms to smooth it out, then roll it in the granulated sugar to coat it completely. This sugar coating adds a delightful, slightly crunchy exterior. Place the sugar-coated balls about 2 inches apart on the prepared baking sheets.

Step 8: Create the “Thumbprint” Indent

Using the back of a ½ teaspoon measuring spoon (or your thumb, if you prefer), gently press an indentation into the center of each dough ball. Don’t press all the way through. The back of a measuring spoon creates a perfect, uniform well for the jelly. If the edges of the cookie crack a little, you can gently press them back together.

Step 9: Fill with Jelly

Carefully spoon or pipe about ½ teaspoon of your chosen jam or preserves into the indentation of each cookie. Using a thicker jam or preserve is key, as a thin jelly can become runny and bubble over during baking. A small piping bag or a zip-top bag with the corner snipped off can make this process neater and easier.

Step 10: Bake to Golden Perfection

Bake the cookies for 11-13 minutes, or until the edges are lightly golden brown and the centers look set. The cookies might appear slightly underbaked in the very center when you pull them out, but they will continue to cook on the hot baking sheet. This is the secret to a soft, chewy center.

Step 11: Cool Completely

Let the cookies cool on the baking sheets for 5-10 minutes before transferring them to a wire rack to cool completely. The initial cooling time on the pan is crucial for them to set up properly. If you try to move them too soon, they may fall apart.