PREHEAT oven to 350° F.
COMBINE cake mix and peanuts 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 (layer will be thin).
BAKE for 15 minutes. Meanwhile, melt chopped Baby Ruth and remaining 1/3 cup evaporated milk in small saucepan over low heat, stirring frequently, until melted. Drizzle over brownie base to within 1/2-inch of edge.
DROP remaining batter by heaping teaspoon over melted candy bar mixture.
BAKE for 25 to 30 minutes or until center is set. Cool in pan on wire rack. Cut into bars using wet knife. Awesome served warm, but great at room temperature too. Top with gummy bugs before serving.