1. Heat oven to 375 degrees F. On a floured surface, roll out and cut pastry into 3-1/4-inch-diameter circles. Place on a parchment-lined baking sheet and poke each circle several times with a fork. Beat together egg and 1 tbsp water and brush over each circle; sprinkle with extra sugar. Bake until golden, 10 to 12 min; let cool.
2. Peel and cut peaches into 1/4-inch dice. Heat jam in the microwave until just hot and pass through a fine sieve. Gently toss strained jam with peaches.
3. In a bowl, stir together the creme fraiche and sugar. Spread about a tablespoon onto each pastry round. Top with glazed peaches and sprinkle with pistachios.