Chocolate Butterscotch Cake

3/4 - cup butter
1 1/2 - cups sugar
2 - eggs
1 - tsp vanilla extract
2 - cups all purpose flour
3/4 - cup unsweetened cocoa powder
1 - tsp baking soda
1/4 - tsp salt
1 1/2 - cups milk
1 - 12.5 oz jar butterscotch ice cream topping
1 - 12 oz container non dairy whipped topping (cool whip), thawed
1 - 3.5 oz box cook and serve butterscotch pudding mix

Preheat oven to 350. 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 medium bowl combine flour, cocoa, baking soda and salt. Gradually add to the butter mixture alternately with milk, beginning and ending with flour mixture. Spoon into 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.