Preheat the oven to 350 degrees (F). Line a baking sheet with parchment paper; set aside.
In a small bowl, combine the eggs and vanilla; mix well. Set aside.
Place the peanut butter in a large bowl and pour in the egg-vanilla mixture. Stir with a large non-stick spatula until combined.
Add the sugar and salt and mix well.
Scoop out 3 tablespoons of dough then roll them together to form one large ball; repeat with all cookie dough. Place the balls 2 inches apart on the baking sheet. Gently press the balls halfway flat and use a fork to make a light crosshatch marks on the top of each cookie. Very gently press down in the center of each cookies with your thumb (not too much or you'll break the bottom of the dough). Fill each indentation with a 1/2 teaspoon of jam.
Bake cookies for 11 minutes. Cool completely on the cookie sheet before moving, serving, or eating.