Preheat oven to 375 degrees F. and line baking sheet with parchment paper.

In large bowl, mix diced peaches with sugar, flour and cinnamon. Set aside.

Unfold puff pastry on lightly floured surface. Cut into six equal squares.

Place spoonful of peach mixture in center of each square. Dot with small pieces of vegan butter.

Fold pastry over to form triangle. Seal edges with fork and brush tops with oat milk.

Bake for 20-22 minutes or until golden brown.

Let cool slightly and dust with powdered sugar before serving.