Process or cut the peanuts into small pieces, set aside.
In a medium-sized bowl, combine the flour, baking soda, baking powder, and salt. Whisk together to combine.
In a large bowl, combine the cooled melted butter, the brown sugar and the white sugar and mix until smooth on medium speed a hand mixer or stand mixer.
Add the eggs, vanilla and peanut butter and beat until smooth.
Stir in the flour mixture in two steps just until combined.
Stir in the chopped peanuts.
Place the bowl in the refrigerator for at least 30 minutes and up to 6 hours so the dough firms up.
Scoop a heaping tablespoon per cookie and roll into a ball, placing on the parchment lined cookie sheet 3 inches apart.
Bake the cookies until very lightly colored, about 15 minutes.
Remove from oven and let stand on the baking sheet for about 2 minutes. Using the back of a spoon or your thumb, create a small indentation in the middle of each cookie.
Let the cookies cool completely, then add about one teaspoon of jam into each indentation.