Chocolate Butterscotch Cake

Preheat oven to 350F. Grease and flour a 13 x 9 inch baking pan. In a large bowl beat butter and sugar at medium speed with an electric mixer until creamy. Add eggs one at a time, beating well after each addition. Beat in vanilla. In a medium bowl combine flour, cocoa, baking soda and salt. Gradually add to the butter mixture alternately with milk, beginning and ending with the flour mixture. Spoon into the prepared pan. Bake for 25 minutes or until a wooden pick inserted in the center comes out clean. With the handle of a wooden spoon, poke holes halfway through the cake in half-inch intervals. Pour ice cream topping evenly over cake. Let cool completely. In a large bowl combine whipped topping and butterscotch pudding mix. Spread evenly over cooled cake. Cover and refrigerate. Cut into squares.