Preheat the oven to 350 degrees. Line an 8x8 baking pan with waxed paper.

In a small bowl, combine together the flour, oats, brown sugar and butter until is well mixed and crumbly. Press this into the bottom of the prepared 8x8 pan. Bake for 13 minutes.

While the crust is baking, take a medium-sized bowl and combine all of the ingredients for the filling. Mix well. Pour this filling over the baked crust. Bake for an additional 20-25 minutes, until the filling is set and a knife inserted in the center comes out clean.

Allow this to come to room temperature, then place the pan in the freezer for 30 minutes. After they are frozen, pull up on the wax paper to remove them from the pan and cut the pumpkin bars into 30 squares.

Using a double boiler or a microwave safe bowl, melt the chocolate chips along with a small chunk of paraffin wax or two tablespoons of shortening. If you are melting this in the microwave, set the time for 15-20 second intervals until the chocolate begins to melt. Then set the time for 10-15 seconds, stirring between each interval until the chocolate has melted completely.

Set one of the frozen pumpkin pie squares on a fork and dip it down into the chocolate. Use a spoon to cover the top and sides of the square with chocolate. Tap the fork on the side of the pan gently a few times so the extra chocolate drips off. Then place the place the chocolate covered treat on a waxed paper lined cookie sheet. Immediately sprinkle the top with chopped walnuts, if desired. The chocolate sets quickly, so be sure you do this right away!

Once all of the pumpkin pie bites have been dipped, allow the chocolate to set completely, then store them in an airtight container in the refrigerator.