Combine cake mix and nuts in large bowl. Stir in 2/3 cup evaporated milk and butter (batter will be thick). Spread half of batter into ungreased 13 x 9-inch baking pan.
Bake for 15 minutes.
Heat caramels and remaining evaporated milk in small saucepan over low heat, stirring constantly, until caramels are melted. Sprinkle morsels over brownie; drizzle with caramel mixture.
Drop remaining batter by heaping teaspoon over caramel mixture.