Red, White, and Blue Cake

INGREDIENTS

• 1 cup butter, softened
• 1 1/2 cups sugar
• 2 large eggs
• 1 cup buttermilk
• 1 teaspoon vanilla extract
• 1 (1-ounce) bottle red food coloring
• 1 teaspoon vinegar
• 2 1/2 cups cake flour or all-purpose flour
• 1 tablespoon cocoa powder
• 1/4 teaspoon salt
• 1 teaspoon baking soda
• 3 cups heavy whipping cream
• 1 cup powdered sugar
• 3 pints fresh strawberries, halved
• 2 cups fresh blueberries