preheat the oven to 350°F.

For the fruits: Dice the peaches and place in a large bowl. Add the lemon zest, lemon juice, 1/2 sugar, and 1/4 flour. Toss well. Gently mix in the blueberries. Allow the mixture to sit for 5 minutes. Spoon mixture in a 8x11 baking dish.

For the crumble: combine 2 cups four, 2/3 cup sugar, 1/2 cup light brown sugar, 1/2 teaspoon ground cinnamon, and 2 sticks of salted butter in a bowl. Mix the ingredients with an electric mixer. Mix until the butter is the size of a peas. Rub the mixture with your fingertips until it's in big crumbles, then sprinkle evenly over the fruit mixture. bake for 45 to 60 minutes, until the tips are brown and crisp and the juices are bubbly. Serve warm or room temperature.