Preheat oven to 350°F. Grease a 9x13 pan. Add together the first 5 dry ingredients and pour into the greased pan.
Make 3 wells into the dry mix. Two small wells and one large.
In one small well place the vinegar, in the other small well add the vanilla and in the large well place the vegetable oil.
Pour coffee and kahlua over entire mix. Mix well with wooden spoon directly in the pan, do not over mix. Place in oven for about 35/minutes.
In mixer whip up the shortening and butter. Slowly add the remaining ingredients for the buttercream. Keep adding powered sugar until you reach the thickness you prefer. Cool cake completely and frost. Enjoy ;)
