My Easy & Juicy Bake Mixed Berry Pie

Ingredients

• 2 ½ cups all-purpose flour
• 1 tsp salt
• 1 tbsp granulated sugar
• 1 cup unsalted butter, cold and cubed
• 6–8 tbsp ice water
• 2 cups fresh strawberries, hulled and halved
• 1 cup fresh blueberries
• 1 cup fresh raspberries
• ¾ cup granulated sugar
• 2 tbsp cornstarch
• 1 tsp ground cinnamon
• 1 tbsp lemon juice
• 1 tsp vanilla extract
• 1 egg, beaten (for egg wash)
• 1 tbsp coarse sugar (optional, for garnish)