1-First Step: Cream the wet base. In a large bowl, beat 1/2 cup softened unsalted butter, 1 cup creamy peanut butter, 1/2 cup granulated sugar, and 1/2 cup packed brown sugar with an electric mixer on medium speed until light and fluffy, about 2-3 minutes. This creates the perfect creamy foundation for tender cookies. Scrape down the sides to ensure even mixing.

2-Second Step: Add egg and vanilla. Beat in 1 large egg and 1 teaspoon vanilla extract until fully combined, about 1 minute. The mixture should look smooth and glossy. If it separates slightly, mix a bit longer; this step binds everything for better dough cohesion.

3-Third Step: Mix dry ingredients. In a separate bowl, whisk together 1 1/4 cups all-purpose flour, 1/2 teaspoon baking soda, and 1/4 teaspoon salt. Gradually add the dry mix to the wet ingredients on low speed, mixing just until a soft dough forms. Avoid overmixing to keep cookies chewy, not tough. The dough will be sticky but manageable.

4-Fourth Step: Shape the cookies. Scoop tablespoon-sized portions of dough and roll into 1-inch balls. Place them 2 inches apart on prepared baking sheets. Use your thumb or the back of a spoon to gently press an indentation into the center of each ball, about halfway through. This thumbprint holds the Nutella perfectly.

5-Fifth Step: Fill with Nutella. Spoon or pipe about 1 teaspoon of Nutella into each indentation. If Nutella is too firm, microwave it for 10 seconds to soften. For extra flair, add a sprinkle of sea salt on top now.

6-Sixth Step: Bake to perfection. Bake one sheet at a time in the preheated oven for 10-12 minutes, until edges are golden but centers are still soft. Rotate the sheet halfway for even baking. Cookies will firm up as they cool.

7-Final Step: Cool and serve. Let cookies cool on the baking sheet for 5 minutes, then transfer to a wire rack. Enjoy warm for the best melty centers, or store as directed. Pair with milk or coffee for a complete treat.