Lemon cupcake recipe with strawberry buttercream frosting

Ingredients

• 1 cup butter, softened
• 2 cups sugar
• 3 eggs
• 2 teaspoons grated lemon peel
• 1 teaspoon vanilla extract
• 3-1/2 cups all-purpose flour
• 1 teaspoon baking soda
• 1/2 teaspoon baking powder
• 1/2 teaspoon salt
• 2 cups (16 ounces) sour cream
• 1-1/2 cups (8 ounces) fresh strawberries, rinsed and hulled (6-8 big strawberries)
• 4 large egg whites
• 1-1/4 cups sugar
• 1-1/2 cups (3 sticks) unsalted butter, room temperature