01 - Set oven to 350°F and line two large baking sheets with parchment paper.
02 - In a large bowl, use an electric mixer to beat the unsalted butter, granulated sugar, and light brown sugar together until pale and fluffy.
03 - Blend in creamy peanut butter, then add eggs one at a time, mixing thoroughly after each addition. Stir in vanilla extract.
04 - In a separate bowl, whisk old-fashioned oats, all-purpose flour, baking soda, and salt until evenly blended.
05 - Mix the dry ingredients into the wet ingredients gradually, beating just until combined without overmixing.
06 - Fold in the chocolate candies, semisweet chocolate chips, and mini pretzels if using.
07 - Scoop rounded tablespoons of dough onto prepared baking sheets, spacing two inches apart.
08 - Bake for 10 to 12 minutes, until the edges turn golden while centers remain soft.
09 - Allow cookies to cool on baking sheets for 5 minutes, then transfer to a wire rack to cool completely.