01 - Preheat oven to 350°F and line two large baking sheets with parchment paper.
02 - In a large bowl, use an electric mixer to cream together softened butter, granulated sugar, and light brown sugar until pale and fluffy.
03 - Blend in peanut butter. Add eggs one at a time, mixing thoroughly after each addition. Stir in vanilla extract.
04 - In a separate bowl, whisk together old-fashioned oats, all-purpose flour, baking soda, and salt.
05 - Gradually add the dry mixture to the wet ingredients, mixing only until combined and no dry streaks remain.
06 - Gently fold in red, white, and blue chocolate candies, semisweet chocolate chips, and mini pretzels if using.
07 - Scoop rounded tablespoons of dough onto lined baking sheets, leaving two inches of space between portions.
08 - Bake for 10 to 12 minutes, until edges are golden and centers remain soft.
09 - Allow cookies to cool on baking sheets for five minutes, then transfer to a wire rack to cool completely.