6 Inch Birthday Cake with Easy Buttercream Flowers

Bahan-bahan (8 porsi)

• 1 and 3/4 cups (207g) cake flour (spooned & leveled)
• 3/4 teaspoon baking powder
• 1/4 teaspoon baking soda
• 1/4 teaspoon salt
• 1/2 cup (8 Tbsp; 113g) unsalted butter, softened to room temperature
• 1 cup (200g) granulated sugar
• 3 large egg whites, at room temperature
• 1/2 cup (120g) full-fat sour cream, at room temperature
• 2 teaspoons pure vanilla extract
• 1/2 cup (120ml) whole milk, at room temperature
• 1/2 cup rainbow sprinkles
• 1 and 1/2 cups (340g) unsalted butter, softened to room temperature
• 6 cups (720g) confectioners’ sugar
• 1/3 cup (80ml) heavy cream or whole milk
• 2 teaspoons pure vanilla extract
• 1/8 teaspoon salt