Add the flour, baking soda, and salt to a mixing bowl, whisk well, and set aside.
Add the flax meal and water to a small bowl, stir, and set aside. Stir occasionally. This creates a flax egg.
Add the butter to a standing mixer with the paddle attachment and beat on medium-high speed for 2 minutes, scraping down the sides of the bowl with a rubber spatula as needed.
Add both of the sugars and continue beating for 2 minutes, scraping down the sides of the bowl as needed.
Add the flax egg and continue beating for 1 minute.
Add the peanut butter and vanilla extract and continue beating for 1 minute.
Lasty, add the dry mixture and beat on low speed just until combined, scraping down the sides of the bowl as needed. Do NOT overmix.
Place a piece of plastic wrap directly onto the dough, cover the bowl with a piece of plastic wrap, and chill it in the refrigerator for 1 hour.
Once the dough is chilled, divide it into 2 tbsp portioned balls.
Roll each ball in the crushed peanuts and then lay them on a large baking sheet lined with parchment paper.
Using your thumb, press down in the center to create a large well. The jelly will go here later.
Set the pan of cookies in the freezer to chill for 2 hours.
Preheat the oven to 350 degrees Fahrenheit.
Line a large sheet pan with a piece of parchment paper and place down a few cookies at least 3 inches apart from each other.
Fill each indent in the cookies with your jelly of choice, about 1 tablespoon per cookie.
Bake the cookies on the middle oven rack for 13 minutes. *The cookies will continue baking and set as they are cooling down on the baking sheet.
Allow the cookies to cool completely before drizzling them with the peanut butter white chocolate.