Preheat oven to 350 degrees F. Lightly spray a 11 x 7-inch baking dish.
In a large bowl, combine the oats, flour, baking soda and brown sugar, mixing well.
Cut in the butter until the mixture resembles small crumbs; press into the prepared baking pan.
Bake the crust 15 minutes.
While the crust is baking, beat all the cheesecake ingredients with an electric mixer until smooth.
When crust has baked 15 minutes, remove it from the oven and let it sit for about 5 minutes to slightly cool (this is important if you are using a glass/ceramic pan due to thermal shock), then pour the cheesecake mixture over the crust.
Return to the oven and bake for 25-30 minutes, or until cheesecake layer is set.
To make the topping, combine the chips and cream in a microwave-safe bowl. Microwave at high setting for 30 seconds; stir. If there are still large lumps of chips, microwave an additional 30 seconds, then stir until no lumps remain and the sauce is smooth.
Pour the chocolate sauce over the top and spread it to coat the entire surface.
Chill until ready to serve.