Add flour and sliced butter to a mixing bowl. Using a pastry cutter, cut the butter into the flour until the mixture is the size of small peas. Add cottage cheese and mix with a spoon until combined.
Using your hands, shape dough into a ball. Cover the dough with plastic wrap and refrigerate for 1 hour.
Preheat oven to 375 degrees.
Place peaches and blueberries in a large bowl. Add ¼ cup brown sugar, cornstarch, and almond extract. Gently toss to coat the fruit. Set aside.
On a piece of flour-dusted parchment paper, roll dough into a roughly 12-inch. Leave the dough on the parchment paper and transfer to a baking sheet.
Spoon fruit onto the dough and spread evenly, leaving a 2-inch border along the perimeter. Fold dough edges over, crimping and pleating as needed. Brush the beaten egg over the dough and sprinkle with 1-tbsp. brown sugar.
Bake on center rack until golden brown and bubbly, about 45 minutes. Transfer to a cooling rack and cool for at least 20 minutes before slicing. Serve with ice cream or whipped cream, if desired.
Notes
You can substitute vanilla extract for almond extract if desired.The dough can be made ahead of time and chilled for up to 3 days. Store leftovers loosely covered at room temperature for up to 2 days.