Preheat oven to 350 degrees. Line a 9x13 inch pan with aluminum foil and spray with cooking spray. Set aside.
In a bowl of a stand mixer, combine flour, old fashioned oats, brown sugar, sugar, baking soda, cinnamon, allspice, and nutmeg. Add the softened butter. Using the paddle attachment, mix until it resembles a coarse meal texture. Sprinkle in vanilla and blend. Stir in carrots and chopped pecans. Reserve 2 cups of the crumb mixture and press the rest in the bottom of your 9x13 inch pan. Bake for 20 minutes.
To make the cheesecake layer:
While the crust is baking, beat together the cream cheese and sugar until smooth. Add the eggs one by one until smooth and lastly add the vanilla. Once the crust is done baking, spread the cheesecake mixture over the top of the warm crust.
Top with remaining crumbs and bake for an additional 25-30 minutes or until the top is golden brown and the cheesecake layer is set. Let cool completely and refrigerate for at least 3 hours for easier cutting.