1. In a large mixing bowl, cream together the softened butter, brown sugar, and granulated sugar until the mixture is light and fluffy.

2. Add the eggs one at a time, beating well after each addition. Stir in the vanilla extract.

3. In a separate bowl, whisk together the flour, baking soda, and salt. Gradually add the dry ingredients into the wet mixture, stirring until just combined.

4. Fold in the semi-sweet chocolate chips and peanut butter chips using a spatula or wooden spoon.

5. For best results, chill the cookie dough for 30 minutes to prevent spreading during baking.

6. Preheat the oven to 350°F (175°C). Line baking sheets with parchment paper. Scoop tablespoon-sized balls of dough and place them spaced apart on the sheets.

7. Bake for 9 to 11 minutes, until the edges are lightly golden and the centers are still soft.

8. Let the cookies rest on the baking sheet for 5 minutes before transferring to a wire rack to cool completely.