To make the topping: In a small bowl, add the sugar and flour.

With a pastry blender, cut in the shortening until mixture is like coarse crumbs.

Add in walnuts; stir and set aside.

To make the cake: In a mixing bowl, cream the shortening, sugar, and vanilla.

Add in the eggs, beating well.

In another bowl, add the flour, baking soda, and salt; stir to combine.

Add the dry mixture to the creamed mixture alternately with the sour cream; stir well after each addition.

Spread half of the batter into a greased 13x9 inch baking dish.

Spread half of the pie filling evenly over the batter.

Repeat layers.

Sprinkle topping mixture evenly.

Bake at 350°F for 50 minutes or until the top is browned and pick comes out clean.

Let cool slightly.

For glaze: In a small bowl, mix together the milk, powdered sugar, and vanilla; Drizzle over the coffee cake.

Cut into squares and serve.