Preheat the oven to 350°F (175°C) and grease a 9×9 inch baking pan.
In a mixing bowl, cream together butter and powdered sugar until light and fluffy.
Add in flour, desiccated coconut, and salt. Mix until well combined.
Press the mixture into the prepared baking pan to form the base.
Bake the base for 15 minutes or until lightly golden brown.
In another bowl, mix together peanut butter, brown sugar, eggs, and vanilla extract until smooth.
Spread the peanut butter mixture over the baked base.
Sprinkle the chopped peanuts on top.
Bake for an additional 30 minutes or until the top is set and lightly browned.
Allow the bars to cool completely before cutting into squares.
Serve and enjoy!