Preheat the oven to 350 degrees F. and line a 9x13 inch pan with parchment paper.
Combine the graham cracker crumbs and melted butter and press into the prepared pan. Bake for 10 minutes, then allow to cool.
In the bowl of a stand mixer, whip the honey on high speed for 3-5 minutes.
Add the cream cheese and beat until thoroughly combined.
Add the cornstarch and pumpkin pie spice and combine.
Add the pumpkin puree, sour cream, and vanilla and mix, then add the eggs.
Pour the filling on top of the graham cracker crust and spread evenly.
Bake for 45 minutes until the center is slightly jiggly in the center, but for the most part cooked through. Then, prop the door open, turn the oven off, and let it sit for 10 minutes.
Remove from the oven and allow to cool completely.
After it has cooled, place it to cool in the fridge overnight or at least for 6-8 hours.
Prepare the frosting by beating the cream cheese and butter until fluffy. Add the powdered sugar and pumpkin pie spice and beat. Add the maple syrup, then add the milk if the icing is still stiff.
Remove the bars from the pan using the parchment paper and spread the frosting over the bars.
Cut them into squares.