Ingredients with an asterisk (*) are available seasonally right here in North Iowa! Click on select ingredients to find them nearby or stop by your local farmer's market.
Process all dry dough ingredients in food processor till coarse. Add butter pulsing the food processor till pea size droplets are left. Add 2-4 Tbsp ice water one Tbsp at a time till dough is moistened and forms a dough ball. Pat into a 1” thick disk and wrap tightly with parchment paper or plastic. Chill for at least one hour. Dough keeps best no more than 3 days.
Preheat oven to 400. Toss peaches, blueberries, cornstarch, lemon zest, cinnamon, and sugar in a large bowl.
On a lightly floured surface, roll chilled dough into large circle- at least 12 inches around.
Lay dough down on a lightly floured baking sheet. Place fruit on top leaving a 1/2” border. Lift dough edges up over fruit. Chill for 10 mins.
Brush top of pastry dough with egg and sprinkle with sugar. Dot filling with butter.
Bake until fruit is softened, and crust is golden brown (40-50 mins). Enjoy!