Begin by opening the can of peaches. Drain the syrup completely and chop the peaches into bite-sized pieces.

In a large mixing bowl, combine the chopped peaches with the dry instant vanilla pudding mix. Stir thoroughly to coat every peach piece.

Add the miniature marshmallows to the peach mixture.

Gently fold in the whipped topping and sour cream. Mix carefully to maintain the light texture.

If using pecans, fold them in gently.

Cover the bowl with plastic wrap and refrigerate for at least one hour.