Add the oats, non-dairy milk, maple syrup, vanilla extract, pumpkin pie spice, ground flaxseed, and salt to a mason jar or airtight container.
Stir everything together until well combined.
Fold in half of the diced peaches and gently mix.
Add the remaining peaches on top or save them to add just before serving for extra freshness.
Cover the jar tightly and refrigerate for at least 4 hours or overnight.
Before serving, stir the Peach Cobbler Overnight Oats if desired and top with chopped pecans for a delicious crunch.
Enjoy cold, or warm gently in the microwave if you prefer.