Preheat your oven to 350°F (175°C) and prepare a 9x9 inch baking pan.
In a large mixing bowl, combine the peanut butter, granulated sugar, and brown sugar.
Add the egg and vanilla extract, mixing until fully incorporated.
Sprinkle the baking soda and salt into the mixture and mix until combined.
Spread the batter evenly in the prepared baking pan.
Bake for 18-22 minutes until lightly golden.
Remove from the oven and immediately press chocolate kisses into the center of each bar.
Allow the bars to cool in the pan for at least 15 minutes before slicing.
Slice into squares and serve.