Good-Cooking - Upside-Down Chocolate Cupcakes

Ingredients

• 1/4 cup butter or margarine, melted
• 1/2 cup firmly packed brown sugar
• 1 tablespoon water
• 36 to 48 walnut halves
• 1 cup cake flour, sifted
• 1/3 cup cocoa
• 1/2 teaspoon baking soda
• 1/4 teaspoon salt
• 1/4 cup butter or margarine
• 3/4 cup granulated sugar
• 1 egg
• 1/2 teaspoon vanilla extract
• 1/2 cup water
• 1/3 cup sweetened condensed milk
• 1/2 cup semisweet chocolate chips
• 1 tablespoon butter