In medium bowl, with mixer on low, combine first 4 ingredients. Increase speed to medium and beat 2 minutes. Pour batter into 2 greased and floured 9" layer cake pans and bake at 350 for 35 minutes or until cake tests done. Cool in pan on wire rack 15 minutes. Poke holes in cake with straw and drizzle evenly with Kahlua. In medium bowl, combine pudding mix with milk and beat at low speed until thickened and smooth. To assemble the dessert: Place one of the cake layers on a serving plate and spread half of the pudding mixture on top. Spread half of the whipped topping over the pudding mixture and sprinkle with half of the crushed candy bars. Repeat with remaining ingredients in same order. Chill until serving.