Step 1: Preheat your oven to 350°F (175°C) and line two baking sheets with parchment paper.
Step 2: In a large mixing bowl, combine the softened butter, creamy peanut butter, brown sugar, and granulated sugar. Using an electric mixer, beat on medium speed until the mixture is smooth and creamy, about 2-3 minutes.
Step 3: Add the egg and vanilla extract to the butter mixture. Beat until well combined.
Step 4: In a separate bowl, whisk together the all-purpose flour, baking soda, and salt.
Step 5: Gradually add the dry ingredient mixture to the wet ingredients, mixing on low speed until just combined. Be careful not to overmix.
Step 6: Gently fold in the chocolate chunks using a spatula until evenly distributed throughout the cookie dough.
Step 7: Using a cookie scoop or tablespoon, drop rounded balls of cookie dough onto the prepared baking sheets, spacing them about 2 inches apart.
Step 8: Place the baking sheets in the preheated oven and bake for 10-12 minutes, or until the edges are lightly golden but the centers are still soft.
Step 9: Remove the cookies from the oven and allow them to cool on the baking sheets for 5 minutes before transferring them to wire racks to cool completely.