Easy Flag Cake Recipe with Berries & Cream Cheese Frosting

Ingredients

• 2¾ cups all-purpose flour, spooned into measuring cup and leveled-off
• ½ teaspoon salt
• ½ teaspoon baking soda
• 2 sticks (1 cup) unsalted butter, softened
• 2 cups sugar
• 2 teaspoons vanilla extract
• 4 large eggs, at room temperature
• 1 cup buttermilk (see note)
• 8 oz cream cheese, at room temperature
• 1 stick (½ cup) unsalted butter, at room temperature
• 1 teaspoon vanilla extract
• Pinch salt
• About 5½ cups confectioners' sugar, divided
• 1 half-pint (6 oz) blueberries (see note)
• 4 half-pints (24 oz) raspberries (see note)