Preheat the oven to 350°F. Grease and line a 9x9 pan.
In your stand mixer, cream together the room temperature butter and peanut butter with the light brown sugar. Beat in the egg and vanilla. Mix for 2 minutes on high. Scrape down the sides.
Mix in the sourdough discard until just combined.
Fold in the flour, baking soda, and sea salt.
Fold in the chips and then spread the batter into the prepared pan.
Dollop strawberry jam evenly over the top and swirl it in with a knife or rubber spatula. Optionally top with additional peanut butter chips or peanuts.
Bake for 35 to 40 minutes. A toothpick inserted in the center should come out crumby but not coated in raw batter.
Stir together 2 Tbsp of jam with 1 Tbsp of water, and use a pastry brush to glaze the top of your bars while they're still warm.
Allow them to cool completely so the center sets. Then, cut into 9 bars.