Preheat & Prep: Preheat oven to 350°F (175°C). Line a baking sheet with parchment paper.
Cream Butter & Sugars: In a large bowl, beat the butter, granulated sugar, and brown sugar until light and fluffy.
Add Wet Ingredients: Beat in the eggs one at a time, then mix in the vanilla.
Combine Dry Ingredients: In a separate bowl, whisk together the flour, baking soda, and salt.
Mix Dough: Gradually add the dry ingredients to the wet mixture, mixing just until combined.
Fold in Peaches: Gently stir in the diced peaches.
Scoop & Sprinkle: Drop spoonfuls of dough onto the baking sheet, spacing them 2 inches apart. Sprinkle each with cinnamon sugar.
Bake: Bake for 12–15 minutes, or until the edges are golden.
Cool: Let cookies rest on the baking sheet for 2–3 minutes, then transfer to a wire rack to cool completely.