Good-Cooking - Colombian Fresh Banana Cake with Sea Foam Frosting

Ingredients

• aspoons lemon juice
• 1/3 cup nuts, finely chopped (optional)
• 2 (1/4 cup) egg whites
• 1 1/2 cups firmly packed light brown sugar
• 1/8 teaspoon cream of tartar *
• 1/3 cup Coca-Cola
• 1 teaspoon vanilla extract
• Dash of salt