Pudding Poke Cake

1 pkg. (2 layer size) cake mix
Topping:
2 pkgs. (4 serving size) Jello chocolate instant pudding and pie filling
1 cup confectioners' sugar
4 cups cold milk

Prepare and bake cake mix as directed on package for 13x9 inch cake. Remove from oven. Poke holes at once down through cake to pan with round handle of wooden spoon (or poke holes with plastic drinking straw, using turning motion to make large holes.) Holes should be at 1 inch intervals. Only after the holes are made, combine pudding mix with sugar in large bowl. Gradually stir in milk. Beat with electric mixer at low speed for not more than 1 minute. Do not overbeat. Quickly, before pudding thickens, pour about 1/2 of the thin pudding evenly over warm cake and into holes (This will make stripes in cake.) Allow remaining pudding to thicken slightly, then spoon over the top, swirling it to "frost" the cake. Chill at least 1 hour. Store cake in refrigerator.