Prepare the Cookie Bars:

• Preheat the oven to 350°F (175°C). Grease a 9×13-inch baking pan or line it with parchment paper.
• In a large mixing bowl, beat together the peanut butter, butter, and granulated sugar until light and fluffy (about 2-3 minutes).
• Add the egg and vanilla extract, beating until combined.
• In another bowl, whisk together the flour, baking soda, and salt. Gradually mix this into the wet ingredients until fully incorporated.
• Slowly add the milk and stir until the dough comes together. The dough should be thick but spreadable.
• Spread the cookie dough into the prepared baking pan, smoothing the top with a spatula.

2. Bake the Bars:

• Bake in the preheated oven for 18-20 minutes, or until golden brown and a toothpick inserted in the center comes out clean.
• Allow to cool in the pan for 10-15 minutes. While cooling, unwrap the Hershey’s Kisses.

3. Add the Topping:

• Once the bars are slightly cooled but still warm, gently press one Hershey’s Kiss into the center of each bar, securing it lightly.
• Let the bars cool completely in the pan before slicing into squares.

4. Serve and Enjoy:

• Slice the bars into squares and serve. Enjoy the chewy peanut butter goodness paired with the melty chocolate center!