Combine flour, baking soda and salt in a medium bowl. Set aside.

In stand mixer, whisk peanut butter, sugars, butter, corn syrup, egg, yolk and vanilla until smooth. Stir in flour mixture until just combined.

Divide dough in half, wrap with plastic wrap, and refrigerate until firm (~ 1 hour).

Preheat oven to 350. Line baking sheets with parchment paper. Roll 2 tbsp dough into balls (~ 1.5 in) and place 2 inches apart on baking sheets. Using the bottom of a measuring cup, gently press each ball to 3/4-inch thickness and top with chopped peanuts, pressing lightly to adhere.

Bake until cookies are puffy and edges are lightly browned, 12-14 minutes. Switch and rotate pans halfway through baking. Let cookies stand on the sheets for 5 minutes before transferring to a wire rack to cool.