flag cake

INGREDIENTS

• 2 sticks (1 cup, 1/2 pound or 225 grams) unsalted butter, softened
• 2 cups (400 grams) sugar
• 4 large eggs, at room temperature
• 2 teaspoons (10 ml) pure vanilla extract
• 4 cups (465 grams) cake flour
• 3 2/3 cups (460 grams) all-purpose flour plus 1/3 cup (45 grams) cornstarch
• 2 teaspoons (10 grams) baking powder
• 1 teaspoon (5 grams) baking soda
• 1 teaspoon (6 grams) table salt
• 2 cups buttermilk (475 ml), well-shaken
• 8-ounce (225 gram) block cream cheese, at room temperature
• 1/2 cup (1 stick or 1/4 pound) butter, at room temperature
• 1 teaspoon (5 ml) vanilla extract
• 2 to 3 cups (240 to 360 grams) powdered sugar
• Powdered sugar
• 1 cup blueberries (1/2 pint, about 170 grams), very dry
• 3 cups raspberries (1 1/2 pints, about 360 grams), very dry