Good-Cooking - Sunshine Pound Cake

Ingredients

• 1/4 cup butter or margarine
• 1 cup granulated sugar
• 1 egg
• 3 egg whites
• 1 tablespoon grated orange zest
• 2 teaspoons grated lemon zest
• 1 1/2 cups flour
• 1 teaspoon baking powder
• 1 teaspoon baking soda
• 1 teaspoon cream of tartar
• 1/2 teaspoon salt
• 1/4 cup lemon juice
• 1/4 cup skim milk
• 4 ounces firm silken tofu, drained