Step 1

Preheat oven to 350 degrees F. Coat a 9- x 13-inch baking dish with cooking spray. Add batter and bake according to package directions; let cool slightly.

Step 2

Using the end of a wooden spoon, poke holes about 1-inch apart all over top of cake. In a medium bowl, combine 1/2 cup melted butter, brown sugar, cinnamon, 1 teaspoon vanilla, and 1/2 cup condensed milk; mix well. Pour cinnamon mixture into holes and spread evenly over top of cake. Let cake cool completely.

Step 3

To make frosting, in a medium bowl, beat cream cheese and 1/4 cup butter until creamy. Add 1 tablespoon condensed milk and 1/2 teaspoon vanilla, and, slowly, beat in confectioners' sugar until smooth. Spread frosting evenly over top of cake. Serve or refrigerate until ready to serve.