Preheat oven to 350 degrees F (175 degrees C). Grease and flour a 9x13-inch pan.
Sift together the flour, baking powder and powdered milk. Set aside.
Cream together shortening and sugar until light and fluffy. Beat in eggs, one at a time, then stir in the vanilla. Stir in the flour mixture until incorporated. Batter will be thick.
Pour batter into prepared pan. Bake in the preheated oven for 40 minutes, or until a toothpick inserted into the center of the cake comes out clean. Prick cake with a fork at 1 inch intervals. Allow to cool.
For the glaze: In a saucepan, combine the sugar, water and instant coffee. Bring mixture to a boil, and cook for 2 minutes. Pour the syrup over the warm cake. Cool thoroughly. Prepare whipped topping according to package directions, then frost cake. Refrigerate for 3 hours or overnight before serving.