Creamy Chocolate Cupcakes

Ingredients

• 1 1/2 cups all-purpose flour
• 1 cup sugar
• 1/4 cup baking cocoa
• 1 teaspoon baking soda
• 1/2 teaspoon salt
• 2 eggs
• 3/4 cup water
• 1/3 cup vegetable oil
• 1 tablespoon white vinegar
• 1 teaspoon vanilla extract
• Filling:
• 1 package (8 ounces) cream cheese, softened
• 1/3 cup sugar
• 1 egg, lightly beaten
• 1/8 teaspoon salt
• 1 cup (6 ounces) semisweet chocolate chips
• 1 cup chopped walnuts