Roasted Berry Poke Cake

Name: Roasted Berry Poke Cake
Prep time: 30 min
Cook time: 30 min
Total time: 1 h
Cuisine: American
Ingredients: 2 cups fresh strawberries (sliced); 1 cup fresh raspberries; 1 cup fresh blackberries; 1 cup fresh blueberries; 1 cup fresh cherries (pitted and halved); 2 tablespoons granulated sugar; 2 tablespoons lemon juice; 1 vanilla bean (optional); 1 cup unsalted butter (melted); 1 1/2 cups granulated sugar; 1 tablespoon vanilla extract; 3 large eggs (room temperature); 3 cups cake flour (substitute all purpose flour); 2 1/2 teaspoons baking powder; 1/2 teaspoon kosher salt; 1 cup whole milk; 1 cup unsalted butter (room temperature); 3 1/2 cups powdered sugar; 1 tablespoon lemon juice; 2-3 tablespoons milk (as needed); fresh berries; flowers (optional)