In a medium bowl, stir together the Greek yogurt, honey, vanilla extract, and cinnamon until smooth and evenly combined. Taste and adjust sweetness if needed.
Slice the peaches into thin wedges, discarding the pits. Sprinkle the peach slices with a tiny pinch of flaky sea salt to enhance their natural sweetness.
In clear glasses or mason jars, spoon a layer of the sweetened yogurt mixture into the bottom of each glass, using about 1/3 cup per serving.
Add a layer of sliced peaches on top of the yogurt, using about 1/2 cup of peach slices per glass and pressing them gently against the sides for a pretty presentation.
Sprinkle a generous layer of granola over the peaches, using about 1/3 cup per serving. Press down lightly so it nestles into the fruit.
Repeat the layers once more: yogurt, peaches, then a final topping of granola for maximum crunch.
Drizzle each parfait with a touch of extra honey, garnish with fresh mint leaves if desired, and serve immediately for the crunchiest texture. If making ahead, keep granola separate until ready to eat.
